The relationship between Buddhism and sexual orientation varies by tradition and teacher. According to some scholars, early Buddhism appears to have placed no special stigma on homosexual relations, since the subject was not mentioned.
Lay followers and monastic practices
In the early sutras of Buddhism, "accepted or unaccepted human sexual conduct" for laypersons "is not specifically mentioned." "Sexual misconduct" is a broad term, subject to interpretation according to followers' social norms. Early Buddhism appears to have been silent concerning homosexual relations.
According to the Pāli Canon and Āgama (the early Buddhist scriptures), it is not specified that same or opposite gender relations have inherently something to do with sexual misconduct, and some Theravada monks express that same-gender relations do not violate the rule to avoid sexual misconduct, which would mean not having sex with someone underage (thus protected by their parents or guardians), someone betrothed or married and who have taken vows of religious celibacy.
Some later traditions feature restrictions on non-vaginal sex (some Buddhist texts mention non-vaginal sex as sexual misconduct, including men having sex with men or paṇḍaka) though some Buddhist monks interpret such texts as being about forced sex. This non-vaginal sex view is not based on what Buddha said, but from some later scriptures such as the Abhidharma texts.
Regarding Buddhist monks, the Vinaya (code of monastic discipline) bans all sexual activity, but does so in purely physiological terms, making no moral distinctions among the many possible forms of intercourse it lists.
Among Buddhists, there is a wide diversity of opinion about homosexuality. Buddhism teaches that sensual enjoyment and desire in general are hindrances to enlightenment, and inferior to the kinds of pleasure (see, e.g. pīti, a Pāli word often translated as "rapture") that are integral to the practice of jhāna.
Buddhist texts
Early texts
Within the earliest monastic texts such as the Vinaya ( 4th century BCE), male monks are explicitly forbidden from having sexual relations with any of the four genders: male, female, ubhatovyañjanaka and paṇḍaka; various meanings of these words are given below. Later, the Buddha allowed the ordination of women, forbade ordination to these other types of people, with exceptions to a few particular types of paṇḍaka. The Buddha's proscriptions against certain types of people joining the monastic sangha (ordained community) are often understood to reflect his concern with upholding the public image of the sangha as virtuous; in some cases, this is explicitly stated. Social acceptability was vital for the sangha, as it could not survive without material support from lay society.
Ubhatovyañjanakas
The word ubhatovyañjanaka is usually thought to describe people who have both male and female sexual characteristics: hermaphrodites (intersex). In the Vinaya, it is said that ubhatovyañjanaka should not be ordained, on account of the possibility that they would entice a fellow monk or nun into having sex. Although it has been seen by some that the category of ubhatovyañjanaka is of later addition to the early buddhist texts, since it does not appear in the early suttas, the Pāṭimokkhas, nor in the early parts of the Vinaya.
Paṇḍakas
The paṇḍaka is a complex category that is variously defined in different Buddhist texts. In the earliest texts, the word seems to refer to a socially stigmatized class of trans-feminine and/or cross-dressing people, some of whom may have been sex workers. Paisarn Likhitpreechakul argue that these people are grouped together with groups who are excluded from ordination as well; those with physical disabilities such as deafness or dwarfism, or those who have committed crimes. "The Story of the Prohibition of the Ordination of Pandaka" from the Vinaya claims that the ban is a response to the example of a paṇḍaka monk with a desire to have sex. Being refused by other monks, he had sex with animal handlers, who then told the wider community and brought disgrace upon the sangha. Since the word paṇḍaka does not appear in either of the early Suttas nor in the early parts of the Vinaya, it has been seen by some as a possible indication that pandaka's inclusion in the Vinaya did not happen in the Buddha's lifetime but was added later.
In the Lotus Sutra, it said Bodhisattva should not go near Paṇḍaka, as like what monk rules said in Vinaya. The Theravadin text Milinda Panha, claims that Paṇḍakas let out secrets through their imperfection.