Ya but... if he actually didn't originally want to (something I considered probable back in the threads for the strips he first appeared in), and if she tries to talk (or whatever ) him into "wanting it", then... seems kind of an entrapment sort of thing to me. (Yes, yes, not "technically", she's not a police officer or anything, but yanno what i mean).
Either her morality routines would have no problem with that, which I would find a bit surprising given what we've seen of Ping up to this point; or else the rainbow hair and weight gain have been accompanied by a lot of internal changes including morality (she's doing stuff she wouldn't have previously considered doing); or else... something else weird.
Yeah I'm with Tiger, I consider myself rather confused at the moment. (I still hold out that the old guy is not an EK client but was meeting Junko for some legit purpose. But Ping is kinda off the rails for me atm )
EDIT:
On the other hand, I did kind of play with the idea of conflict between Ping's moral code and her desire to dish out the pain to the well-deserving in an ancient rescript. So it would definitely be funny, I have no disagreement with that.
Whether the old gentleman actually deserved the beatdown or not would only determine whether it was Deadpool kinda funny or Monty Python...