I'm looking for this yaoi where two friends are in love with each other but they don't kno...

I'm looking for this yaoi where two friends are in love with each other but they don't know about it. And there's a teacher. The first guy is extremely close with the teacher which gives the second guy a wrong idea about them. Later for some reason the first guy thinks the second guy is in live with the teacher but it turns out the first guy is close to the teacher cause he is getting married to his sister