Lily calls him out (Patreon)

I think of this as a reunion of step-children, meeting up again after a few years, 5 or so, separated after their individual parents had a messy break-up with one another. She can't wait to show off all her obvious physical changes since the last time they were under the same roof while he looks quite the same but somewhat bigger and not in a positive way, She also would love a little hardcore revenge for all those years of bullying and mental torment he inflicted upon her when he took his father's side while she, a few years younger and much smaller nonetheless, took her mom's side. Sometime he would just sit on her head and fart while playing some video game or hit her in the stomach and laugh when she doubled over. He was then and continues now to be the epitome of a lazy fat douche bag. She had just begun her training back then near the end of their time together it is so time for some fun personal payback.

Lily also recalls his weird secret fetish, cosplay, from back when they lived under the same roof, especially fighter game cosplay. Being an obsessive video gamer, that's how he achieved such an appropriate physique in his later teens, she knows how much an outfit and the body beneath it probably turns him. Obviously his fighting skills are strictly limited to his dexterous thumbs while her training prowess go well beyond her upper digits and a game controller.