Steph is not a physically attractive person in the slightest, her without make up is a really disgusting sight lbr, and her personality is even uglier.
Jeremy is limited in his choices and because he's arguably racist he didn't go with Tiffany, if Stephanie thinks she'd stand a chance with Jeremy on the outside she is mistaken he'd drop her like THAT if they got together in the house.
Best of a bad bunch (for him, at least
)