I think it's a QT. I only read a few chapters before I lost my bookmark. So I'm not too sure how much of this is accurate... The MC's mum is marrying the ML dad and the MC is a "dragged oil bottle". He is sticking to his character settings. I don't think the ML's dad loves the MC's mum. The ML comes from a wealthy family. I think they were meant to ride home together but the ML told him to walk all the way home and not to take a cab/public transport. The MC doesn't want to disrupt his character settings or grab attention (wants to remain a background character) so he walks home. The ML is out (at the mall?) and sees the MC walking and realises he didn't call a cab/take the bus and thinks the MC is interesting.
No, but thank you for replying! I only read a few chapters so if it is a QT (which I'm sure it is) this would have taken place in the first arc.