So I decided in this AU,Mark likes/has a crush on 3 people but he act differently towards each person,he has his normal attitude towards Benjamin,his kinda sweet & nice attitude towards Lilly,& his Tsundere,kinda rude,but nice,kind,& mostly/kinda friendly attitude towards Ash.
Mark loves all 3 of them but he can't decide so yeah it's a love square or triangle in this AU.

Edit:"this will change a bit since Steven is in the picture now"