The youngest baby gays in a friend group, who are often spoiled and doted on because they are adorable, and still learning. Often times can be found asking for places to nap, and unlike real babies change their own diapers (usually).
A term that shouldn't exist because it's dumb and also the most petty thing that has been said for a while. It's also worse than just saying "baby" because the term baby is already not putting someone in a gender category where saying "theybie" is putting them in the non-gender category
Theybie is a gender-neutral way to refer to one's child or to a young nonbinary person. Originally coined by parents who wished to avoid imposing societal gender-roles their infants, it has more recently been adopted by nonbinary people for use not only to refer to one's children, but also to an enby of whom one is fond, just as "baby" is a term of affection.