Also a word used in a out of the blue outburst to alert others among a group of guys when a hot girl is spotted by one of them. The meaning in this situation is the person with the outburst would like to get freak nasty with the woman.
When properly pronounced the words are to be recited in a higher pitched tone with a Ebonic accent.
Baby I'm home and its Mr Nasty Time!!!
Damn look at that chick, Mr nasty time!!!