Had similar happen to me.

I was 19, in first year of college in the city I grew up in. I had a skateboarding friend who went to a different high school than me and was a year younger than me. So, he was still in high school at this time. He would come over for drinking and would sometimes bring over friends from his school.

I really hit it off with this one girl who went to school with him. She wasn't my normal type (I had a blue mohawk, piercings and into punk. She was the typical preppy girl). We hung out a bit on the weekends without him. She eventually asked me to prom with her. I said sure. Got my suit dry cleaned, ironed a shirt, trimmed up the mohawk. I was going to look awesome. I picked a black shirt with a white tie to go with my black suit. She was going to wear a white dress with black accents. I thought I did good.

She had a few small requests. Since I was of liquor age, she gave me money to pick up booze. (For me.. I swear I didn't buy underagers beer....), asked if we could take my vehicle (I had a mini van) and if I could dye my hair to a more normal colour. Did it all. Dyed my hair black (max matching skills, yo)

I get there to pick her up, her entire family is there. Like...aunts, uncles, grandparents, cousins... The whole lot. She made a last minute change to a pink dress. (Red flag one). Bitched to me about how her pictures were ruined now that we didn't match. Wondered why I brought a mini van and not something nicer. She knew what I drove, and I was taking all her friends, too. What did she expect? A limo? It was discussed we would take my vehicle. (Red flag 2). Her friends proceeded to make fun of me for being too poor to afford a better vehicle. (Red flag 3). Should have just up and left there.

Get to the prom, she leaves me. Danced with me once for 30 seconds to get a picture, then ignored me until it was time to leave.

She was asking me to drive her about 45 minutes to another town to party. Some of the guys started to get pissed with her and one said that his mum was the manager of a nearby hotel and would give us discounted rooms. We went there instead. Where she got pissed at me for having a cigarette (first one since I picked her up about 8 hours previous, she knew I smoked and asked me not to smoke at the prom, which I did). That was it for me.

I grabbed a bunch of the booze, went to one of the rooms, watched a movie and got shittered. A bunch of them went to the pool, one of the other girls came back to the room with me and cuddled. It was a nice end to an absolute shit day.