Lick me if you can novel

Can I pls ask you how are the characters of lick me related to this couple? It's been a while since I read work from this author so I'm a bit lost.

they are Chase’s parents! Ashley and Koi, they have their own story and kinda you can see how they treat their kids and stuff, mostly their family dynamic and traumas lolol, so you can see why the millers are crazy

Okay thanks!