derived from the singer Ville Valo due to his curly hair and hat.A flopsy is always male and often has an arched back.
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."