I know exactly how you feel.

My partner of 17 months went out for the first time to a reunion and didn't get home until 3am ! He had accidentally dropped his cell phone in my car when I was dropping him off to the bar at 7.30pm. He did Facebook message me via a friend once to inform me that hopefully I would find his phone in my car - which I did. Apart from that we had zero contact and omg I was so anxious especially as it was just so late. We had an argument as my mind worries he might wander with other ladies etc etc (at least you don't have that issue).

He is now saying he will NEVER go out alone again and that makes me feel sad as I want him to be happy and not sit on a Saturday night listening to me breathing fast and acting like a zombie on meds.

I guess we just need to relax more !!! Easier said than done huh.