"So far in this account I don't think Buddhism in practice comes to startlingly different conclusions about sexual conduct from those of balanced versions of other major religions. But the other religions also have lists of no-no's, of forbidden sexual practices. Some object to partial or total nudity, or masturbation, or cross-dressing, or sado-masochism, or homosexuality, or fetishism, or premarital sex, or oral, anal or group sex, or contracepted sex. Buddhism is notorious for its habit of putting points of practice and doctrine into lists. So where is Buddhism's list of naughty sexual practices?

The answer is short and sweet. Buddhism doesn't (for once!) have a list."

(http://www.buddhanet.net/winton_s.htm)

It simply states "don't do sexual misconduct" and leave the details to the practictioner for the details "sexual misconduct" means. And the guidance to determine that is "do no harm" (no deceit, manipulation, etc)

So consensual sex between two adults are in. Things like do harm like adultery in marriage, phedophilia, rape, etc are out.

Sexual orientation is not detailed in Buddhism - gay or straight - no biggie.

Buddhism itself is a very conservative religion and its standard for moral ethics is very high. We don't have a concept for forgiveness for our sin for example. The 'karma system' simply states if you are bad, you will reap the fruit later on. There is no last minute pardon.