My daughters dog will be nearly 6 months old when he goes to stay with friends for the holidays but they are worried because they have a girl that is not neutered and may possibly be in season during his stay.He will be getting neutered but will still be entire during his stay.Would he be interested in girls at that age and would it be advisable to keep them apart should her girl come in to season.I have no experience with boys so any advice appreciated,thanks.

He'll be plenty old enough to mate with her, so yes, if she comes into season they will definitely need to be kept apart.

Oh yes, ready, willing and able :)

As an entire dog owner I wouldn't want any of my boys staying at a house with an in season bitch.  I wouldn't even allow my neutered boy to stay.  You'd be asking a lot of an inexperienced owner to keep dog and bitch apart but it's also not fair on the boys to waft that under their noses. 

In addition to the risk of an accidental mating many boys won't eat during this time, can howl, and also be destructive in their efforts to get to the bitch.  The bitch plays her part too and can be quite ingenious in an effort to find a mate!

If there is a very real risk of her being in season during your daughters holiday I'd suggest they make alternative arrangements for their boy.

Regarding neutering, if this is the pup you've been taking about recently, then this op could adversely affect his coat to say nothing of the impact on his growth and development.  Neutering should be left until until he is fully mature. 

My mother in laws dog mated a bitch when he was only 4 months old, so at 6 months old he will be more than capable. :-(

To put it in as simple a point as possible, the moment a males balls drop he can mate it can happen anytime from 3.5 months onwards depending on how quickly he should develop. Just as in humans there are early and late bloomers. :-)

Yes he is the same dog ive been talking about recently and although my daughter plans to have him neutered it wont be done until he is a little older.we do have a back up plan but this friend was desperate to look after him because he is a sweetheart but not if it will upset him or the girls in any way.