A person who finds romantic urges towards both men and women but only find sexual interests in the same gender. He or she will enjoy going on dates, hugging, cuddling, buying stuff for their other, and possibly kissing, but they can only be aroused in sexual intercourse with the same gender.
A biromantic homosexual female would date men and women, but usually only "go to bed" with other women.
Boy: *Experience a slight kick*
Boy: Ur ancestors incestors
You: *Goes flying 50 feet away*
You: *cough* ur family reunion is a homosexual communion
Boy: *Screams in pain then fades from existence