I am understanding “???? and ???? ???” as meaning flirtatious talking or behavior (???? ???) and playing or having fun in a non-platonic manner (“????”).
I am sourcing it primarily from the meforshim on Shulchan Aruch, Yoreh Deah 195:1 and Avos 3:13 and Rabbeinu Yonah thereon. My understanding of kalos rosh also comes from the way Rav Moshe uses it when discussing the need for a mechitza.