Oh I would have been upset over this. I would consider this very rude that he left me sitting there worried not knowing what was going on. How much time does he actually need with his friends? You have to stop and think do you have any respect for how I feel, it would take less then one minute to text me.

In a relationship you need honesty ,trust ,AND communication .I think its healthy in a relationship to have a girls/guys night out.but it should be in moderation.and not overshadow the couples date nights. A simple call or text to say hi n I'm thinking about you while your out helps solidify the trust with each other .a simple gesture that says thank you for giving me my own time but your always # 1 in my life

Time apart is healthy, now if he is using that time to AVOID hanging out with you then it is probably a bad sign, but the fact that you are asking for a specific time in hours makes me think you want to regulate his 'boy's time' to a specific amount of time, that will end badly.

Men need to be around other men on occasion, it is necessary. But sometimes women misinterpret boy's night as 'pick up ladies night' guess what? if it's a boy's night probably not so much. Boy's night often means doing something that your SO may not be willing/want to do. Example, going to a UFC fight, or playing a sport, or simply just going to the bar to play pool and eat and drink.

Now in your scenario of him saying going to lunch, and not coming back until 3:30am, i'm guessing it wasn't only boys there, but that's my opinion.