"Many of us didn't have a wild youth, settled down early, etc. It's not a fate worse than death".
I have only ever slept with my now husband. I met him in my teens and we were each' first serious relationship. I love the fact that I didn't go through the same drunken sexapades as my friends, endure the same heartaches, worry about whether I would ever meet the one all through my 20s and early 30s. I loved that we got on the housing ladder early before prices went crazy, that we travelled together etc. I have lots of friends in the same position. There are lots of positives of settling down early. It's pretty immature to suddenly regret those decisions that you made and enjoyed/benefitted from at the time. You didn't hold him hostage. He made those decisions because they obviously suited his character.
What makes him think that, if he'd shagged around in his 20s, he would have got it out of his system? In reality he would almost certainly still feel as though he was missing out, when he had to stay in and look after the kids. Because, let's face it, looking after young children is relentless, frustrating and suffocating at times. It's a tough slog. But also a rewarding one. I'm sure that many men (and women) miss their freedom when they have babies and young children and would love to be out letting their hair down and absolve themselves of responsibility. Most don't however, because they are sufficiently grown up to realise that they chose to have children and have responsibilities towards them.
He's being very immature in the way that he is selectively choosing to compare what he perceives to be the best parts of others lives with the more mundane of his own, whilst discounting the best parts of his life and ignoring the worst parts of others.
I also like the use of the word 'peeping Tom's that someone used. It takes the perceived glamour out of 'voyeurism'.