Someone who enjoys behavior typically associated with dating and love, like cuddling, hugging, gift-giving, love notes, but probably not kissing, etc. and enjoys it with both genders, without necessarily desiring subsequent sexual experience. Biromantic people can be straight, bisexual, homosexual, or asexual.
Jane went out with a girl and bought her this beautiful bracelet. Then they cuddled and watched a movie at her apartment. They don't make out or anything like that. They only desire physical relations with men. They must be biromantic and heterosexual instead of bisexual.