DP and I have a mutual friend who is a similar age to us. He is divorced, with kids aged 10-15, and we've been friends with him for a few years now. In that time he's had a couple of relationships, one serious and we helped him through that very difficult breakup. All these relationships have been with women of a similar age to us aswell.
He recently got a new girlfriend, his first since the serious relationship breakup, and contacted DP wanting to meet us for a drink so he could introduce her.
We met last night, and I admit I was shocked when he arrived with an 18 year old woman. A very young looking 18 year old too, who was lovely although seemed young for her age aswell. Turns out DP knew her age but didn't tell me, which in itself I find odd.
Friend and girlfriend seem to get on well, they met through a mutual sport that he teaches and she is a student of. She mentioned that she is about to choose her university for this September, and that she has decided she is going to go to the one in our town (she lives about 100 miles away with her family). The driver being clearly to move into friend's house with him and his kids.
Although it was all pleasant enough, I found the whole situation unsettling. DP and friend kept making jokes about things she was too young to understand, then saying things like 'oh but you're too young' and then pointing out that I would understand them. She didn't seem bothered by this but I found it uncomfortable and not impressed with DP's behaviour or friend's.
I had a chat with DP afterwards and said I found it all a bit 'icky', surely there would be a power imbalance and in honesty I found it a bit difficult socialising with them. He's dismissed what I said, saying 'as long as they're happy', which I can understand, but it still doesn't sit right with me. Our own children are mid teens and I pointed out he wouldn't be happy if in a couple of years one of them started dating a much older man and moved away to be with him.
I've said I don't really want to socialise with friend now, although he has always been nice and girlfriend was lovely. DP thinks I'm completely overreacting.
Am I overreacting?