>>33398227 (OP)Because it's a creepy thing to say to a woman who isn't interested in you. Women instinctually don't like to know you're leering at them if they don't like you like that, because it means your lust may overtake you and, as a male, you can overpower them. They'll see you as a threat. That's why they tell guys "in their tribe" they feel safe with "ew this creep keeps looking at me" etc. so they can tell him to fuck off or kick his ass.
So basically, you're unattractive and being a weird creep. You should work on both those things. Start lifting, dressing better, and learn to not be socially awkward.