It looks a little ridiculous when it's cold out or winter time. It wouldn't make you look fun or flirty it would just make you look kinda weird and silly (not in a good way ). However, in summer time they do look fun and flirty. I love how they look in shorts! :)
Anyways, on a date to the movies? Yea maybe. But only in warm weather. It is a little casual for a date of that kind but I don't it's necessarily unacceptable. I still think it could look cute. Just make sure he knows exactly how casual you are going. :)
... nope. Flip flops are for children or budget beach hollidays.
... Sorry. Flip flops in winter go right into blotchy legs (as in bare legs getting blotchy from cold... normally displayed in a bustop) territory (things you often see and make you feel simultaneously proud of how odd some of the people in your fine country are, and sort of ashamed that you live there).
As long as you are not wearing something party formal, flip flops are extremely flirty and fun BUT ONLY if the feet are pretty and clean and well kept. Dirty, dry and/or "flawed" feet can in fact be a MAJOR turn off.