I?d be flattered, or think they?re joking, since I?m not attractive (the most I could say is that I?m skinny and have been told by a few girls that I have ?nice eyelashes?, but I have a shit depressing personality and my stutter can make it hard to converse with even my friends) and have never been hit on (at least, to my knowledge).
Chances are, if I knew they weren?t fucking around, I?d give them a creepy grin like I always do to girls I like, take them up on it and ask them out to the cinema or something, because I?m a desperate, lovesick virgin and I might be too embarrassed/inexperienced to just come out and say, ?Hey, I think you?re pretty too; wanna go out with each other?? If anything, it?s usually me that?s checking others out.