My guess is it's just an expression and the use of the word 'dog' is irrelevant. If one mistakes a snarl for a yelp, one can wind up finding teeth in one's ass.

One also starts to wonder if saying women aren't interested in sleeping with them because they're post-menopausal is the geriatric version of "if she doesn't want ME, she must be a lesbian." The post-menopausal thing is true in some cases, I think. In others, a woman who's sufficiently interested would, I'd think, at least want to want to. If the relationship is such that you can't both at least talk about it, it's not a very good one anyway.

I've known (no, I didn't mean "known") lots (ok, what I really didn't mean was "lots") of guys who went for the sex first, and then waited to see if an emotional relationship grew out of it. This might work if you're 20-something, but it might not be very successful in beginning a relationship with those of us who're economizing on hormones. It might not work anyway. It might help to change one's approach, but it's very hard for an old dog (didn't mean anything derogatory by that) new tricks.

Haha! Listen to me...single, and as far out of the dating loop as I can get without falling off the edge of the planet.