I haven't dated in years, but probably the worst was about twenty years ago. The guy asked me out, but informed me that as a starving student, he couldn't afford my movie ticket so we'd have to go Dutch. (I was 21 at the time; he was about 25). It wasn't the going Dutch that bothered me; it was the way he worded it.
Anyhoo, we went to see "Crocodile Dundee," which was just coming out in the theaters at the time. And the seat I chose to sit in was, unbeknownst to me, broken, so that when I sat down in it, it collapsed. Very embarrassing. But instead of being a gentleman, this guy BURST OUT LAUGHING and announced to the entire theater that I broke the seat. Needless to say, it was our first and last date, and in fact it was about the last heterosexual date I had in my entire life. LOL
The worst date with a woman? Ye gads, what a tale. We were sitting in a restaurant and the Muzak was playing that song, "Drift Away," that goes, "Gimme the beat boys to free my soul/wanna get lost in your rock 'n' roll and drift away," and I noticed that my date was singing softly along with the music. Except she was saying "wanna get lost in your p***y hole." OMG. I was SO grossed out that I wanted to just DIE. Need I say this was our last date? ROFLMAO
Actually, my last date was about five years ago and it was absolutely magical, Cinderella stuff. She was attractive, paid me glorious court, and it was a supremely romantic evening. Two days later, she told me she actually had a girlfriend that she'd, oops, forgotten to tell me about. LOL
The way I figure it, since I've sworn off dating now, I did have a lovely last whirl. I just choose not to remember how it ended up.