I forgot the title please help find it.

I'm looking for a BL Korean manhwa where the uke pretends to have experience with girls in front of his college friends. There's a particular scene where he demonstrates how to kiss, but the seme knows that he's just pretending. Later, when they get together, the seme realizes that the uke is probably afraid of girls because of his sister and also the uke is afraid that the seme will avoid when he knows the truth that he was only pretending to have experience.