On Days Of Our Lives How did Chelsea Brady find out Daniel had slept with Grandma Kate?

I know it was a little while ago but all I can remember from the episode (I think) is Chelsea getting ready to seduce Daniel or whatever at his place/bedroom & I think Kate called his phone or something & Chelsea heard something she was "not supposed to hear". Any1 remember? Help please LOL. NOT the time she found out about Nick Fallon & her mother Billie but as if that wasn't bad enough! Then Kate had to go after her granddaughter's love interest. AH Kate makes me sick but does any1 remember how Chelsea found out about her & Daniel? Poor thing, first her mom, then her grandma. I am glad she's with Max now even if she & he are no longer on the show & he is her step uncle!