Hand him a book and he'll bury himself in it. He's never been interested in a formal career because he's too busy learning. Chastity has always been able to convince him to put down the book and dance.
At the start of the game, Gabriel may very well have a romantic preference for his best friend, Samantha Cordial. If you have a Sim move into a lot close to the lots where they live, if both of them appear in the welcome wagon to welcome those Sims into the neighborhood, one of the two may perform a romantic interaction. If that happens, they will end up falling in love on the scene. Often going unnoticed, Gabriel has eyeliner and light lipstick.
When the family is first played, he will be 26 days away from becoming an elder. He is very close to becoming fat, and will run the risk of becoming fat if he overeats, and hasn't improved his fitness level beforehand. Oddly, Gabriel has no memory of aging to a teen and apparently he had his first kiss as child, and by his memories he would have been a teen then, though that is not possible in normal gameplay. This may have been a mistake made by developers, or a glitch.
Gabriel is known to be the shoving Sim when a Sim from another household stargazes with a telescope during the day. This is because Gabriel is the first playable Sim created in Belladonna Cove. If Gabriel stargazes with a telescope, Geoff Rutherford will be the shoving Sim instead. He has a pregnancy modifier token which will increase his chances of having twins.[1]