You turned him into panties, and decide to wear him. Since he became girl's panties, you need to be a girl to wear him properly. But this doesn't puzzle you too much. Your waist and dick shift in and your bully becomes attached to your hips. You push him extra tight to your groin, flat groin.
You both will get used to it. And unlike your bully, you are still human. He in turn, is merely your underwear, attached to your wet private parts.