Mainly as Bart yes, but there should be some moment where you play as Marge too! And possibly if I got a great idea and just for the time of a scene you might possibly play as Homer.
Overall Bart will be the main protagonist, the one that have his way with Marge and other woman of the town, but there will possibly be scene where other male charater had good sex scene too, but it will me more late and probably more for what I call "what if story" (but not only).