I admit, I'm a control freak and I used to be a bit of a bitch when DP went out with his mates.
Nowadays, Im pretty good at keeping my mouth shut and trying to be positive when he goes out. But then I just tie myself in knots all night and end up fuming. I'll take it out on him at some point... maybe send him an attention seeking text while hes out, or try to stop him having a lay in the next day. It's horrible, I know it's wrong and I want to stop.
E.g. He is going out tonight. Tbf he NEVER makes plans to go out - his friends ask him. And for the past year and a half he's rarely gone out drinking. He used to go out a lot more often and let me down quite a few times e.g. Coming home later than planned or not coming home all night 
I went out last night, so it's not like I don't socialise (although I didn't used to when he was out all the time). I've planned a 'nice' night for myself... Think bath, takeaway, early night etc. yet Im still anxious and annoyed about him going. His friend is single and is always on the pull and it makes me mad just knowing they'll be chatting to girls (although DP is a bit shy in these situations and I wouldn't describe him as a flirt - he certainly wasn't when we first met and obviously he was a young, single guy then!).
No matter how calm I am at the beginning of the night I'm always seething with rage when he stumbles in at stupid o clock smelling of booze.
How can I just be normal about him going out? :(