I need help finding a specific manwha(?)

what is the manhwa where the girl is a brunette and the guy is a blond and they first met at a dating app where they had a phone sex and they met each other irl but didn't know it was them but the guy is actually an asshole but he got physical problems on the elevator and the girl helped him and they live in the same building. the guy is living at the top of the building which is the most expensive one and such. when they knew it was each other that they are chatting the blond guy softens up and then they had sex i think and then the guy is younger than the woman and lied about it

That's all I knew from mind before I forgot about it and it was like, 2 years ISH ago.