This happened a while ago so not really an AIBU but a WIBU.
I took my partner away for a long weekend for his birthday. Planned, booked, and paid for by me.
I drove us there (4 hours), sussed out the parking situation and booked the restaurants/made evening plans.
From the moment he woke up that day (day before his birthday), he was in a foul mood. Complained about having to pack (had left it last minute), complained about how long the drive was (I was driving), spent AGES complaining about the parking situation (secure underground garage which he deemed wasn't safe enough/cars were parked too close to each other. my car though so why was it his problem?), complained about the AirBnB, complained that the restaurant I had planned for lunch was shut and we had to go elsewhere. You get the idea.
Anyway, we went out that evening for drinks at a live music venue. The band were fantastic and we (I) was having a lot of fun drinking, dancing, chatting to another group of guys and girls. It was a brilliant evening. My DP obviously didn't agree and he got spectacular drunk. He wasn't throwing up or unwell but he was falling about, making an arse of himself and just needed to call it a night.
I took him back to the AirBnB which was actually just upstairs from the live music venue, made sure he was alright and in bed, made sure he had water and his phone if he needed me, then went back downstairs again for a couple of hours (I had just ordered myself another glass of wine before DP started acting silly and the barman said he'd keep it for me coming back).
This was around 8pm so I wasn't ready for bed and didn't want to sit around the flat on my own (and quite frankly I was sick fed up of him by this point), so I don't think I did anything wrong by going back out again.
DP obviously disagreed and I got the silent treatment the rest of the weekend and accusations for months after of "abandoning him" and cheating on him and he told his parents it was his worst birthday ever.
All irrelevant now, really, but WIBU for not standing vigil by his bedside all night?