Face-planting taxis sounds familiar. :D
Actually, come to think of it there were two occasions with the same woman (who's no longer in this city but still kind of in touch) where I embarrassed myself, and one was on ketamine, where I kept taking special care to open up the glass partition door in the middle of the room, which was somehow only visible to me. Took half an hour before she finally informed me the game was up and I didn't need to open the glass door.
It would've been funny, but the previous weekend she'd finally got herself drunk / desperate enough to invite me home, where I'd talked so much shite about myself on coke (and nipped out for so many spliffs) that she actually fell asleep before we got a chance to do anything.
A beautiful window of opportunity slammed in my face, if you'll forgive the wilful irony.
In the recent past, I had a habit of flirting with the girlfriends of a friend's professional clients, which was fun for me at the time but must've damaged his prospects once or twice.