I know two reasonable definitions, one social and one biological.<br />
Social: someone whose sexuality (involuntarily) harms someone else.<br />
Biological: someone whose sexuality harms his ability to reproduce.
To me, it means someone who doesn't want contact :)
Making crude comments about u or other women. Makes you feel awkward really about things he says. Stares women up and down ( blatantly) in front of his gf or so.