From GLSEN Encourages Teens In Anal SEX "Don't give up." [Free Republic]:
""Doing it: Gay men...Many people don't know the anus is not only an organ to remove waste. It's very sexually exciteable...Your first few times having anal sex might be a little hard. You may have to practice a bit before it starts feeling really good. I sure did." (pg. 81)"
(Also see Reply #182 in the same message thread)