This is ridiculous, people should be allowed to do whatever makes them happy, so long as it does not harm another, and no, being offended is not the same as being harmed.
CR90, there is no evidence to back up your statement that homosexuality is caused by some sort of trauma, being sexual or otherwise. As of now there are many theories as to what causes homosexuality, but there is no consensus on any one.
Here's an interesting one, saw it on dateline or a similar program: if you are a male, and you mother had given birth to a male before you (older brother), it has been found that you are more likely to be homosexual. For some reason the sames results are not seen in those who have an older sister, or in female homosexuals with an older brother, those populations are just as likely to be gay as anybody else. But in the case of a male having an older brother their chances are much higher statistically. As of now there is no scientific explanation for this, there are theories about hormonal changes in the womb after the mother gives birth to a boy, that would somehow effect the development of a second boy, but that has not been proven. This phenomenon however does suggest that homosexuality may have a physiological cause that happens during the development of the fetus.
Here's a little bit on that:
http://www.newscientist.com/article/dn9413-male-sexuality-may-be-decided-in-the-womb.html