Did the seme just said he also like the girl?

Nope. She is an ex girlfriend of woojin

But the seme said to the girl that he still like her because he got a big heart

The author aid it in one of her twitter.

They're friends to each other after they broke up because they don't have the same feelings look for her twitter you will see.

But the seme said he still like her becuase he got a big heart idk if he meant he still got an extra room for the 2

I don't know what your pointing at, but honestly I don't think he like her in a romantic way because his obsess to HG so (=・ω・=)

Ch 24 pg 9 i reread it and i thought seme said "i have a big heart blah blah" it was actually the gurl talking my bad i thought he said that he meant i still like you because i have a big heart