Does the man playing the female role also transgress?
Torah Temimah (citing Sanhedrin, 54b): Yes! And we learn it from the words "Lo "Sishkav" which can also read "Lo Sishacheiv".
Ramban: If so, "uv'Chol Behemtecha Lo Sisten Shechavtecha" should forbid also females. Why was a separate verse needed for females?! We cannot learn from Lot. He was inert due to his inebriety, so she needed to move his body to make the semen come out.
What is the underlying reason behind the prohibition of homosexuality and bestiality?
Ramban: Intimacy with them is abominable and cannot produce children. 1
Moshav Zekenim citing R. Yehudah ha'Chasid: The Torah forbids homosexuality, so men will marry women and fulfill Peru u'Rvu.
Why is this called "To'evah"?