I live in a mid size city and go out frequently. It's small enough that I regularly run into girls anywhere on the spectrum from "we've been texting and she stopped responding" to "we hooked up for a few weeks" to ex-gf. Despite a lay count approaching 70 I still consider myself to have a long way to go in that I get nexted more often than I do the nexting. So the majority of these girls I run into have at some point rejected me rather than the reverse.

Usually when I see one such girl out, I'll just give them friendly hug, maybe talk for a couple minutes, then go back to my friends and eventually start approaching new girls if the venue is appropriate for it. Am I being too friendly with girls who rejected me? Would it be better to just ignore them and do my own thing? Or should I be a little bit of an asshole and tease them about something, maybe something fun sounding but a little pointed?