Sex is any activity that one engages in for erotic pleasure or reproduction. Sex is still sex whatever the gender, orientation, preferences, or number of the participants.
Safe Sex is sex which holds NO risk for disease transmission or injury.
Fantasy, masturbating yourself, hot talk, and non-sexual massage on healthy skin are examples of this category. Vaginal or anal intercourse with a condom, and oral sex or rimming with a dam fall into this category. Unsafe Sex is sex which holds a HIGH risk for infection or injury. Anal or vaginal intercourse without a condom falls in this category. Basically, you should avoid any situation in which the body fluids of another person might get into your bloodstream.