inside their apartment where the couple are talking

Mitsuri: obanai-san I have some good news I wanna tell you!

Obanai: o- oh well I have some bad news I wanna tell you...

mitsuri: o- oh how about we go at the same time?

Obanai: okay three...two...one

Mitsuri: meet my sister Y/n! Motioning to the door

Obanai: I- I cheated on you with Y/n! He said in unison