Is this right ?

What do you think about about 18 year old girl being with a 30 something year old man ? Does its make any since ? 
S/N he's sleeping on the floor at his cousins house & she's right along with him, they don't have jobs, nothing going on for themselves.
The crazy thing is she has a bedroom at her moms with a bed and everything but she wants to lay on the floor with a guy that has nothing.
They also one time got in an argument & she burned his cover inside the house that's neither or theirs