I think it all depends on the other person. If he's very confident in his own sexuality, he not only shouldn't be offended, he should consider the attention a compliment.<br />
On the other hand, probably most people would feel threatened. They might feel threatened because they aren't settled yet with their own sexuality (such as being a closet queer and being terrified of anyone finding out), being homophobic, unexperienced, of just not a sexually driven person. <br />
I think it's pretty much the same with women. Those who are confident will be seeking attention and love getting it. Those who are not confident or inexperienced, might feel threatened. Funny how so many women will wear really revealing clothing - clothing that would get them kicked out of most churches, or arrested in a Muslim country - to show off their assets. Yet when some guy does notice, many girls don't know how to handle it and feel threatened. It's their psychosis, not yours.
I'm a gay guy and think if you do it carefully, so that they are not aware you are staring, that's ok.....but to STARE obviously? that's a no-no.......<br />
I am really into guy's butts and I may have an advantage...at the supermarket if I see a really hot butt I can stare and stare to my heart's content, because it looks as though I'm looking for something on the shelves!!!!!......<br />
But you really should be a little polite when you stare at those great crotches!! I do, too, but always try to make it look 'innocent'.....
It is offensive to me. Why do beautiful women not like you to only look at their "assets"?
I'm straight, but I've always been comfortable around my many gay friends. Personally, I don't mind being checked out, because it doesn't happen to straight guys very often, at least not openly. Most women are more sly about it. So yeah, in most cases, I find it flattering.<br />
I check out pretty much every attractive woman I pass, but I do it subtly, not overt and obvious.