Is it MORE insulting for a girl when her boyfriend leaves her for a guy?

With the wild popularity of the Philippine drama series My Husband's Lover (who is a guy), came a string of comments, perceived and imagined, saying that it is a lot more insulting if a straight woman's spouse/lover leaves the relationship for a guy and not another woman (or a woman and not another guy, from the straight man's perspective).

From: www.bubblews.com

I totally understand the insult which comes from infidelity. You gave your trust, he/she broke it. It is painful. It is your fragile self, your truest self, thrown away by the one you love after you have given it wholeheartedly. To that extent, I understand. I sympathize even. No one has the right to cheat on another. But what I find stupid and unacceptable is when people say it's much more insulting when it turns out that his/her lover is homosexual. 

"Mas okay na kapag babae ang pinagpalit sa akin kaysa sa kapwa niyang lalaki," said an imaginary ginang in my mind. (But, to be fair, I have been hearing this even outside my own imagination.)

This notion is wrong for a couple of reasons: first, because it is never okay to cheat, and second, this comes from the implicit idea that gays, lesbians, and bisexuals are inferior to straight men and women. 

One's manhood or womanhood gets damaged if a lover cheats. But, it is more devastated when a lover cheats with an LGBT. Clearly, there is a double standard, and an unacceptable one at that. We say that all men and women are born or "created" (whatever) equal regardless of race, belief, and gender. Yet in the same breath we say that it is unacceptable, immoral, insulting if one is in a gay relationship. Then what does it mean to be homosexual and at the same time equal in dignity with heterosexual people?! 

Ginang/Ginoo, the next time you comment about your favorite drama because of the controversy and thrill that you get from its novelty, and not from the more important lesson that homosexuality is inevitable, better make sure you don't use your manhood/womanhood first before your brain.