Second Life Sex leads to Real Life Divorce
A couple in the UK have divorced when the unknowing wife caught her husband having virtual sex with a prostitute in Second Life.
To have sex in Second Life, one must buy genitals to 'strap on' to ones self and then user created movements can emulate sex.
Some purchased genitalia can even mimic ejaculation.
Reference: 'How do Avatars have sex?' - BBC