I'd had a crush on a guy I worked with for some time. He asked me out a couple times but flaked out at the last minute both times. I'd basically decided to give up on him when he called and asked if I wanted to meet him and his friend at a bar. I went and met them and we were all having drinks when he asked me if I'd like to accompany them to a party.

His friend immediately said, “Man, you can't bring her to that party.” They started arguing back and forth and his friend ended up storming out of the bar.

Obviously I was pretty confused about what was going on and said, “Look, if it's a problem, I don't have to go”. My date assured me that it was fine. He had just briefly dated a woman who might be at the party, she was sort of obsessed with him, etc. He told me he was pretty sure she was out of town though and there'd be no problem. I stupidly agreed to go and he offered to drive us both.

We got to the party and everyone stopped and stared at us as we entered. Super awkward. Then my date just started ignoring me completely and became very cold towards me. Eventually he just disappeared entirely. I walked outside and his car was gone. He wouldn't respond to calls or messages.

I then came to find out that the party was being hosted by the girl who was 'obsessed with him’ at her house. From her I learned that they'd been dating for several months and had actually had sex earlier that day. Luckily the girl was really nice and realized I had no idea of her existence and we both agreed the guy was a jerk. I called a taxi and made it home from the party and, obviously, never spoke with the guy again.