This is a matter of propinquity and individual preference. This is risky even if both parties are unmarried and sure of their potency. If it is not completely straight and completely satisfying, respect is soon cremated in the heat of ill-spent passion, and the ashes of respect are the burning embers of scorn. Such an ill death of something fine is seldom worth the hazard. This is a good way to get an autograph from an admired one.
Affectionate sex is groovy.
A good way to share the room rent, some people think. Nothing interferes with friendship like sex, and nothing interferes with sex like friendship. Intimate sex is wow. Sexual fluids make a good cement, and they also produce babies. This was from the section on Classifying Relationships.