Yes, the police "frisk" someone to search for weapons. But "frisk me" is used as a flirty or "naughty" invitation for someone to touch you in a sexual way (in sexual body areas).
"Hey, Mark. I've been a VERY bad girl today. I think you should frisk me."
Or, it can be a cheeky dare. Imagine that a teenage boy is bothered by his mother's constant questions about whether he is using drugs. If she asks him if he was smoking pot, he may turn around, spread his arms wide and say, "Do you want to frisk me?"
The adjective "frisky" comes from first definition that romulus gave above. But, it ALSO has the connotation of the SECOND definition now. So when we say someone was "getting frisky", it usually means both playful AND sexual -- sexual in a playful way.
Ex.: "My wife was unusually frisky tonight, but I wasn't complaining!"