If someone did that to them in a pub, would they drop like that? Of course not, so for that reason it's trying to con the ref and therefore cheating. Yellow card.
I remember when Bony did that once. He was shit for the whole game and had been pretty much since we bought him and he scored with, if I remember, a simple tap in after and amazing assist, and he went to the crowd and did just that whilst the rest of the team surrounded the player who provided...