Why all of you call the new guy daddy ?? And how can know that he is married ???

In one of the panels in the previous chapter, his ring finger on the left hand had a ring. And for the daddy thing, I personally think there's this "daddy" vibe from him. But I was just joking around with the daddy thing haha

Ohh you’re right ! I didn’t see it lolll maybe his mother remarried (or just married) with him

She doesn’t mean that guy is Sangho’s step-dad necessarily; it’s a word used to describe a dominating male figure in a (usually sexual) relationship.