Anterior motives OP IMO sorry
What's an anterior motive when it's at home?
OP, it could be genuine or not but either way, this probably isn't the first time he's done this, in fact he probably does it a lot and for that reason alone I'd find it grim.
Not keen on men who sleep around.
I'm of a generation that missed out on the whole handing numbers over on a slip of paper thing. To be honest, we're shit at dating so maybe there was something in it,
but I'm always a bit wary when a random man approaches on the street or such like.
I always assume he's just after whatever sex he can get.
I was once approached by a random much older quite handsome man on the street (He was in his 40s, I was in my 20s) and was very politely asked for coffee, he said he'd seen me about most weekends and wanted to introduce himself and thought we could get to know each over a chat. It really freaked me out and I said no, I was busy with uni and wasn't looking to date (then went home and had a laugh with my boyfriend about it). Turns out he was a very well respected member of the community and all around lovely man who lots of people know. I'm still ribbed over a decade later about turning the town's most eligible bachelor down but I don't regret it at all. He made me feel uncomfortable and I'm not that keen on pushy, "forward" people.
For every "romantic, love at first sight fairytale" story there's at least 3 scam
or sexual violation stories from random man encounters. It's right to have your wits about you.
Be flattered and bemused, at least there's no harm in that. I doubt it was a bet, but his intentions most likely weren't great.