Went out for a work bonding event. A group of us ended up at a bar afterwards, then back to colleague's place to call taxis home (let's call him X). I hadn't had very much sleep the preceding few days so climbed into X's bed to have a snooze whilst I waited for another colleague (Y) to call us a taxi which we were meant to share (I had lost my phone earlier that night). X later climbed into bed with me, and a lot some drunken fumbling occurred, although I made it clear I wasn't going to have sex with him. No idea how much time passed, but I realised I hadn't heard from Y and jumped out of bed to look for him. It later transpired that Y had already called a taxi and left (yes, I gave Y a bit of an earful and he has remorsefully apologised - he was told I was in bed with X and thought he was being discreet by not coming to fetch me). I eventually got X to order me a taxi and I went home, showered, and went straight back to the office.
Did not see X all of that day, though a few emails were passed back and forth (thanked him for calling me a taxi, mild joking about how exhausted everyone was in the office etc) though neither of us mentioned what happened.
So, I'm relatively new in this job (I did some consulting for them a couple of years ago, but have now been employed as a permanent member of staff). X is not that much older than me, but is more senior than I am. Yes, I find him attractive but my life is too complicated at the moment to want to eff it up with a work jolly - plus, I'm trying to cement my place in my department and don't want to develop an undeserved reputation (don't know if he would tell anyone, but it wouldn't surprise me if he did). I have decided to just pretend that night didn't happen, deny it if anyone brings it up and carry on as normal. Good, no?