Right, Im a noob to online gaming and used a technique I saw.. My current convo (Private messaging) is:

Me: We spoke to each other briefly last Saturday, right?

HB9: Dont think so mannnn

Me: I thought we briefly said something to each other at Oceana. No?

HB9: No I wasnt out babe x

Me: Ha! Okay. Well you have an evil twin out there then! I'm trying to decide who is better looking but your personality is definitely starting off better! LOL

HB9: ahaha Lordy what did my twin do?

BAM!

Im stuck :L Dont know what to say already! should I say something witty/funny or create small talk after I reply? and how should I reply to this anyway?

Something like
"We got ourselves aquainted and had a good time "
OR
"We had an amazing time! you should have seen how drunk you got!"
OR
"You started hitting on me and I never even got your name!"

you've already implied some kind of undesirable personality attribute so it would be consistent to keep that theme.