Whatever you do, don't talk about a girls weight, even in a positive way.
I was talking to this one girl for a good hour and a half at a bar once and things couldn't have been going better. For some reason, she started talking about how her outfit made her look "a little chubby". It totally didn't, so I said "What? You're crazy. You're not fat at all". To which she replied in a very angry tone, "I never SAID I was FAT"...and that's the last we spoke.
:dunno: