From your post, I'm not sure how often this is happening.
In our house, my hubby has guy night occasionally -- wing night every 2nd or 3rd Thursday with his buds. He doesn't drink alcohol to the extent where I worry about him getting home safely, etc. He STARTS work at 5 a.m. and there are times where he gets only 3 or 4 hours of sleep. But that's HIS problem! lol I do not stay up waiting, worrying and wondering. He's a big boy and can do as he pleases. I trust him completely.
I think once a child enters the mix, women find it hard to swallow the bitter pill that they are TIED to the children, do not, perhaps have the amount of flexibility to "up and leave" so to speak. The man assumes they will be home, caring for the kids, safe and sound, etc. You need your nights out as well (Maybe not til 4 in the a.m.!) I think women are wired differently and if I would add up all my time in a week long period that I engage with, talk to, email, etc my girlfriends it probably roughly equals O. wing night of 4-5 hours that my hubby does. See what I'm saying? I mean I'm not keeping score, but guys generally don't do the daily chit-chat, email, etc with their friends like we do....
I think you need to figure out WHY this bothers you. Do you trust him? Do you suspect he can't say "no" to "O. more" drink and this may become an alcohol issue? Do you feel that you are restricted to the house? Are you worried about DUI? Identify WHY this bothers you specifically and tell him. For example, if you worry about him drinking and driving, talk to him about doing a DD thing. If you feel ignored, plan some family/couple stuff for a night when he's NOT too tired.
I'm pretty independent, so the "he'll go to bed as soon as our son is in bed" thing would not really bother me at all. So what? O. night he goes to bed early? That would not affect me in the least. I'd just be doing my own thing.
How you deal with/react to this now is going to have huge impact on your marriage. Is he a responsible, good husband and father?
My hubby is an awesome husband and father, a great provider, and he works his BUTT off 60 hours per week so I think he more than deserves to go blow off some steam every week or every 2 weeks. As I said, I trust him and I never worry about where he is or what he's doing.
Good luck!