A person who has multiple personalities and is a bit schizophrenic
The persons mood can switch like the wind
I met a guy on AA the other night. He was really flopsy.
A casual date (usu. a young woman) invited to dinner (or drinks or a weekend away, etc.) in order to make up numbers rather than out of any genuine romantic interest.
Jules: I didn't fancy going alone so I called up a random flopsy.
Adjective descriding an endearingly awkward but attractive guy.
Emmy: "That guy is so awkward, but its kinda cute!"
Clara: "i know! he's totally flopsy!"
When a person (typically a girl) sticks her thumb up man's butthole and flips around his balls between her fingers.
"Ryan just told me that Sarah's flopsy giving abilities are unmatched!
When a man and a women are about to have sex, but the man loses his erection when his penis contacts her vagina
"Man I was about to get some last night but I went flopsy."
When your shorts, boxers, or briefs are just loose enough for your man-junk to fall out.
Oh man, I sat across from grandma at the barbecue and had a flopsy. She TOTALLY saw the frank and beans