You call homosexuality a "flaw" and an "abnormality" on the basis that it is sexual behavior that cannot result in reproduction. Well, so is masturbation.
No, I never said it was on the basis that it is sexual behavior that cannot result in reproduction. I said it was an abnormaility because it prevents (or at least seriously hinders) an organism from passing on its genes, masturbation does not have this effect.

What do you mean "we" have genes that make us avoid homosexuality
No, I meant 'we' have genes that make us pursue hetrosexual behavior.

Are people who have had vasectomies or tubal ligations medically abnormal? What about women who have been through menopause? They can't reproduce even if they have sex.
They choose to have a vasectomy, if they we're born with tied tubes (I dunno what the real term is lol) then yes but they choose to do this. Well I think it would be abnormal if a woman reproduces in their 70's. Because the genes cause the menopause.