How do I politely deflect come-ons from dudes I'm not sexually interested in without being rude?

I'm a friendly dude who tries to be warm, candid and engaged when talking to other men. Some will mistake this for flirting, start hitting on me, or even talking about how they'd like to get naked or "swap fluids".I'm not a prude, but it's a real turn-off because I prefer to get to know a guy and actually like his personality before getting physical, but I haven't figured out how to deflect such comments in a way that isn't overly dramatic or rude.How can I convey that I'm not interested without being a jerk? Thanks for any advice.