I kept a bitch from a litter I had, she lives at home with her mum. Pup was the alpha of her litter (not massively so, was a litter of four and the only consistent sign of this was how she would look over her litter maters in the pen and be head look out etc)
Pup is now 17 weeks, my sister had one of the male pups and he recently came around to visit his mum and sister. The two pups naturally were very excited and both very happy to play fight as they had done up to 8 weeks. male pup tends to be chased for a short time before rolling over onto his back and continuing the fight. On occasion it seemed to get a little to boisterous - going for the neck when he was pinned on the floor. As soon as I separate them he would then gladly coming charging back at her and want to carry on the play fighting. The vast majority of this is no different to how the litter all played together or how bitch still plays with mum on a daily basis, however it can get a little too much. They get on fine at other times, been on a walk together and happily walked side by side on the lead, they were also quite happy to curl up and lick each other before falling asleep next to one another once they've got the excitement out of their system.

Just wondered if anyone had any advice or thoughts on this? Should I be concerned and separate them when it gets too aggressive or am I worrying over nothing? Is it too early to have him visit?
Bitch is very well behaved, very social with other dogs on walks - her recall at the moment is very good both at home and out and about. The only time she ignores my command is when the two of them play fight.

A lady in another village had one of my dogs litter mates, a male to my female. I got to know her and we met up several times to give the puppies some playtime. He was bigger and stronger then my dog and always had her on her back, but she relies on cunning to win most times. Sometimes it did seem to get too much and we would part them for a while. We didn’t meet up that often probably a lot less then you meeting up with your sister and her dog.
What we did do though was find a trainer who did one to one training and asked if he would have both of us for a course of training. Our wants were to be able to call the dogs off one another figuring that if we could achieve this then it would be easier to have recalls off other ‘strange’ dogs. The two puppies got on extremely well and developed their own play style which was never used if playing with other dogs.
It took time and a lot of practice, but we were able to call our dogs off one another successfully which continues to this day.
Now if they meet up they play for a while then go off sniffing, unfortunately despite being neutered the male does insist on humping Isla as much as he can, she doesn’t tell him off, just sits firmly on her bum and gives him dirty looks

Look into one to one training that will take both of you, could help enormously

yeah that's a good idea. sort of hoping it will calm down a little and they are both just getting used to each other again. bitch has had the advantage of practising daily with mum for a couple of months so perhaps taking him on is much easier. seems strange that he is so happy and keen to carry on the fighting but also willing to roll over. guessing its part of him knowing she's the boss or on her territory. she rolled over for him once but that was when she was tired from a walk and he'd been sleeping while she was being walked

I always stop and separate pups past 8 weeks once play gets rough. Even if the pups are taking it as playful other dogs won’t appreciate rough play like that. And you need to help teach that/those pups boundaries and to help read other dogs body language. A good recall is perfect to use in this situation. My suggestion would be to have them play on long lines and when play gets too rough recall and encourage them to come back to you - good treats are great for this, or even to come back to play with a toy with you is a good reward. Siblings are especially rough with each other because they know they’re siblings!

We found been similar when my gsd pup met up with his litter sister. We had to separate if and when it got to rough .
As they wernt meeting very often and as time went on due to other commitments less and less it wasn't an issue that we needed to deal with in the end

Pup was the alpha of her litter (not massively so)

Do you mean you consider she was a"dominant"puppy in the litter?

You do realise that truly dominant dog does NOT physically do things like "Alpha" roll other dogs to prove it's dominance. The behaviour you describe is normal puppy behaviour & not a sign of dominance or submission.

In my 60 years of dog ownership I have had just one dominant one & I did not realise this until I saw her subdue a mini squabble between two older dogs with a look & a raised head movement. I had always considered this bitch to be a quiet individual, who was highly tolerant of other dogs, subsequently I realised that other dogs knew how far they could go with her, because of her "status", even dogs from outside her"family"group.

madforlabs - yes thanks will give a try, otherwise she has such a good recall at the moment I don't want to set her up to fail. she's very food motivated

Ann, yes sorry dominant would probably be more accurate - and even then it was only very subtle in the litter. I only really mentioned that as a possible explanation for the males behaviour. she never rolls him its always him just throwing himself to the floor, wasn't really sure if it was submissive etc or just his way of playing. he wants to carry on the fight as much as her - even after he has been pinned and I've pulled her from him.
They've only met a couple of times since he left at 8 weeks so had quite a time apart, just wanted to check there wasn't anything else I hadn't considered

I find (as a trainer) it's not very productive for siblings to continue to meet up regularly past 8wks. There's a reason the litter all go off to new homes and there's a reason littermate syndrome is a nightmare...!

My experience has been that pups allowed to play roughly like this with other pups and become over-familiar with them (as tends to happen with littermates who know each other incredibly well) is that the play gets very intense and involved and this can get transferred across to other dogs - who the pup then expects to be able to play with in the same way.

Example: I have a cockerpoo pup in my puppy play sessions at the moment whose owner has been meeting up with 2 siblings every week. She says they play incredibly roughly and in a hyper way. In class, this pup was at first very cautious and timid around the other puppies (since exposure to littermates does not provide socialisation to a range of other dogs and isn't much use for socialisation purposes as the pups already know each other deeply), and then the pup wanted to play in the same over-involved way with the other pups in the play sessions.

The risk is that 'this type of play is what we do with all other dogs' becomes the take-home message, regardless of what the other dog in the encounter wants. The idea of the dialogue of two well-adjusted dogs meeting - 'would you like to play/meet? would you? hi, who are you? (warm up)' and so on - all that tends to get either totally forgotten about as the pup launches itself in play on the dog, or massively abbreviated to 1-2 seconds.... before launching...

Really, I think briefer exposures to a wider range of dogs is way better than long play sessions with other pups to the point that the pup becomes over-familiar with them... I wouldn't really want to let siblings play together at all because there's not much to gain from it socially. But if this is difficult (due to them also being in the extended family), I'd try to take walks together, and go out where the environment is going to take some of the attention and so it's not just all about the other dog.

Agree completely.

I had a pup back at 12 weeks (relationship breakdown).

I had kept my Inka (now nearly 13) from the litter.

It was a nightmare, they were so full on, even Mum, Grandma and Great Grandma were shell shocked.

Luckily a good friend with same breed offered to take him until rehoming.

He ended up going to the Isle of Man a few weeks later to someone with an older male.

that all makes a lot of sense, thank you. they were at least capable of sleeping next to each other and were fine on a walk together with both on leads. they will likely see each other perhaps once or twice a month. I was hoping/assuming just their own general training will calm them down a little. But I will certainly manage the meet ups now and just keep them to walks on leads and let them get used to being around each other without any fighting and understand what is expected.
My girl has her walks in a very busy dog walking area and meets 2-3 new dogs each day, her behaviour towards them has been - I certainly don't want her just launching into that behaviour with other dogs.

many thanks for all the replies guys, much appreciated. I'll update in the future (hopefully with good news!)

My daughter's border collie met up with her siblings regularly at agility shows in the camping area from a young age. They have never had any problem with these pups interacting with other dogs. Possibly the fact that all these puppies lived in homes with other dogs and experienced owners helped. One of the other puppies is owned by a close friend of my daughters so they have met up frequently for the whole of their lives. The play was a bit rough as puppies but too much rough behaviour was not allowed and now at 7 years old they just play in the same manner as any other unrelated dogs would.