You nor anyone on this forum can prove that homosexuality actually exists.

Homosexuality:
1 the quality or state of being homosexual
2 erotic activity with another of the same sex

Homosexual:
1 of, relating to, or characterized by a tendency to direct sexual desire toward another of the same sex
2 of, relating to, or involving sexual intercourse between persons of the same sex

If you think that none of the above exists, then you don't come from our reality, and you might be getting a bad connection that's routing you to our time-space continuum where such things and states actually do exist. You might want to call your internet service provider. It might be solar flares, or you might need to check your TCP/IP setting (or whatever it is you have in your reality).