What puts me off? Well there are internal and external things. Appearence wise it has to be teeth. I had a brace as a teen and i'm so glad I did, I just think its a massive shame that really attractive women who look amazing let themselves down when they smile. I feel bad for judging someone on their looks but teeth are a factor.
But internal its a bit weird, like I was speaking to a girl a few days back in a club and she brought up how she loves cats and how she collects clothes for her cat, kinda like a mothering complex. I K closed her but I wouldn't of gone any further because she was a no go. I mean I collect stuff heck i've seen every episode of stargate but I wouldn't tell someone that if I was attracted, I'd let them find out after a few months
As for a girl wanting sex on a first date well it depends how I was, if I really wanted to bonk then I wouldn't care but if I was trying to find my sole mate and I had a bang a few days before I would probably back away... unless she was a big 10, then i'd just slip on my rubber and do the deed regardless.
That's my opinion anyway.