Here's some excerpts:
Although twenty-six of the sonnets are love poems addressed to a married woman (the "Dark Lady"), one hundred and twenty-six addressed to a young man (known as the "Fair Lord"). The amorous tone of the latter group, which focus on the young man's beauty, have been interpreted as evidence for Shakespeare's bisexuality, although others interpret them as referring to intense friendship, not sexual love....
....The most commonly-cited example is a number of comedies, such as Twelfth Night and As You Like It which contain comic situations in which a woman poses as a man, a device that exploits the fact that in Shakespeare's day women's roles were played by boys. While the situations thus presented are heterosexual in terms of the story, the stage image of men wooing and and kissing may well have been titillating to those of a homosexual orientation, and while other dramatists occasionally used the same device, Shakespeare seems to have had an exceptional preference for it, using it in five of his plays.
Kinda Interesting. :)