Are you gay
if so why

Yes.

Explanation: Apparently it's because:

"The hereditary link of homosexuality has long been established, but scientists knew it was not a strictly genetic link, because there are many pairs of identical twins who have differing sexualities. Scientists from the National Institute for Mathematical and Biological Synthesis say homosexuality seems to have an epigenetic, not a genetic link.

Long thought to have some sort of hereditary link, a group of scientists suggested Tuesday that homosexuality is linked to epi-marks — extra layers of information that control how certain genes are expressed. These epi-marks are usually, but not always, "erased" between generations. In homosexuals, these epi-marks aren't erased — they're passed from father-to-daughter or mother-to-son, explains William Rice, an evolutionary biologist at the University of California Santa Barbara and lead author of the study

"There is compelling evidence that epi-marks contribute to both the similarity and dissimilarity of family members, and can therefore feasibly contribute to the observed familial inheritance of homosexuality and its low concordance between [identical] twins," Rice notes. "  

"https://www.usnews.com/news/articles/2012/12/11/scientists-may-have-finally-unlocked-puzzle-of-why-people-are-gay

exercising at a moderate intensity, and slowly increasing the duration.