Liraaaa

Can someone help me find the sauce about this Bl manga. It's about a student who is an assistant to his lecturer, and the student falls in love with his lecturer, the student has a friend who is dating his high school teacher. And there's a scene where they meet at the playground

I forget about the title, i think it's bl manhwa, the uke have a boyfriend and he gives all the money to the boyfriend, but the boyfriend will have wedding with a girl, and the girl is sister for the future boyfriend. Please someone tell me the title