Unicorns 🦄

Correct me if I’m wrong. Aside from being an awesome mystical creature, a person who says they are a “unicorn” is someone who is open to being a third in a sexual relationship. Am I getting this right? On tinder (etc), couples are looking for unicorns (thirds). So should I assume that if someone has a unicorn emoji on their tinder, bumble etc. that they might be open to being a third (like for a threesome just to make that clear) thanks ✌🏽