@Giaammyy Sussyy would it be though, people under hypnosis can give consent. This may not be an accurate representation of hypnosis because (SPOILER ALERT) at the end of season 1 he quite literally doesn't want to have s** w/ his older brother.
And plus the party bedroom scene could also be a another reason why he agrees to having s*x with his younger brother, he wasnt under hypnosis and he let it play out. He could have screamed and get his brother in trouble for actually graping him. But he didn't.