while junsu was talking , trying to soothe mrs . jung , he felt yoochun lean in closer and wrap an arm around his waist.his breath caught , and he nearly missed the question , " junsuyah ? do n't lie to me . who 's jaejoong ?

Why did Mrs. Jung ask Junsu about Jaejoong ?
Mrs. Jung asked Junsu about Jaejoong because she thinks Junsu is cheating on her .