1 .
You are about to be introduced to another friend-of-a-friend: this time, a lively-mannered man who is clearly full of interest and experience ('the life and soul of the party'). Your friend tells you quietly, just beforehand, ' ... But do be a little careful; sometimes he can't keep his hands to himself'.
What are you supposed to be careful of, as you go to meet him?
He tends to steal things (picking pockets, etc.) when the chance presents itself.
He is sexually predatory, and will try and touch (probably, young and/or female) people in uncomfortable ways and places under the pretence of being friendly.
He will be likely to move too close to you for comfort, 'invading your personal space', fingering your clothing / jewellery etc., which you may well find disconcerting.
He has a very strong, firm (and perhaps, long) handshake ... don't let that take you by surprise!
A truly responsible friend would probably not take you near any such person in the first place, but it is still worth 'knowing the code'.
Among young 'society girls' in the past, there was a whole such code where they shared experiences about young men they had met. If the initials 'NST' were mentioned, this apparently meant that such-and-such a young man was 'not safe in taxis'; i.e., that he had been known to take advantage of the semi-private environment to 'make a pass' at a girl.