Whilst up the pub yesterday, my boy pup met two springer spaniel bitches.He got on famously with the younger one who had just turned 1. She was in season and my boy couldn't really control himself (if you know what I mean) and he kept trying to mount her and she was inviting him by standing there with her tail to one side, by this time I was highly embarrased! He often mounted her at the wrong end! He is 14 weeks old today. I am a bit worried, but other owners up the pub seemed to think the behaviour was normal. I would love to hear your opinions and knowledge on the subject :-)
Thank you for your time guys!

Yes, it's normal, and it's absolutely wicked of the people in the pub a) to have an in-season bitch out in public, and b) allowing a pup to get so worked up. You may have great difficulty with him in future if temptation is put in his way like this - he could become aggressive and a wanderer. Besides, he's not very far off fertile age. Why on earth didn't you take him away? You have to be responsible for your dog - if you don't like what he's doing, stop him.