A person who is romantically attracter to two or more genders, but will only feel sexual attraction when a deep bond is formed between them and their partner.
"I really liked <person> for a long time, but I didn't develop a sexual attraction towards them until <period of time> after we started dating. Before then I wasn't really interested in or driven by sex, or their gender. I'm a biromantic demisexual."
Person 1: hey man lets have sex Person 2: I'm demisexual :/
Person 1: ....wat
Person 2: I'm not sexually attracted to you unless we have a very strong emotionalconnection.
Person 1: oh cool. wanna talk instead?
Person 2: sure lmao