"A slightly weird love story", eh? I'd say so, but I'm always happy to see some Vanilla goodness.
I must say I was kind of expecting and hoping for an ending where he remembers what happened and decided to...push his relationship with her forward a bit earlier than the original timeline? I think that would have made for a rather interesting story.
Wait, did he see a possible future, or did he temporarily time slip into the future and actually have sex, which led him to confess and immediately want to have sex?
...or did he accept sketchy medicine from a lady on the street, and these are his drugged out delusions. What were actually seeing is how his mind perceives being sexually assaulted by said lady. Think about it. And don't take drugs from strangers kids.