Look her up and down then return to looking at the paper and say "No thank you, I've already had gonorrhea"
look at her and say "Definitely
, oh....er....one question though, are all the girls in your family hot? it's just....well....I tend to go through families like a recessive gene, you know, you, your mum, OMG pleeeeease tell me you have a grandma!...oh no wait, ok, if you have a great grandmother and a baby sister I'll just drop to my knee and propose to you right now"
"I'd definitely be interested
oh but hold on a second, damn, wait right there?" *walk off*
*I look up at her, then break into a smile, grin widely and laugh, looking around her happily* "oh this this is so funny, ok ok, don't tell me, beeeeehind the tree right?, no?...hmmm...that building maybe? oh no wait! do you have one of those tiny cameras on you? oh come on it must be somewhere, this is a joke right? lol, I know! my brother put you up to this right? wow he's good, he just knows me too well, theres no way in hell I'd EVER go out with you lol, oh dear, he's such a kidder, I'll get him back though don't worry. .....ok, I give up" *look at her* "wheres the camera?"
if she runs or walks of really upset i'll then say "...what?" in an innocent and oblivious way.
one that I've actually used before is "No, I'm good thanks, but thanks for asking
"
*sighs and looks up getting out his wallet* "okay, what's your rate? my regular charges $10" *looks her up and down "pff, and shes faaaar more attractive than you, $2.50 sounds generous don't you think?"
"isn't there a water hydrant you should be pissing on?"
look at her in awe and say "wooooow, living art!.......picasso?"
"sorry, my shots haven't been updated yet"
"huh....damn, karma does exist, I knew there had to be some sort of a repercussion for shooting and killing all those people"
"I'm sorry....but have I wronged you in some way? I was just minding my own business and for (as far as I can tell) no good reason you come into my field of vision"
say in a snobbish voice "I'm sorry but I don't very much care for you at all"
"damn...well I guess all those STD's I never bothered to go to the doctor about finally caught up with me...when it's your time it's your time I guess, hey....don't you usually have a scythe?"