'This Is Us' Brings Back a Familiar Face From Kevin's Past -- Is She the One?

etonline.com:

, «Four Fathers,» Kevin (Justin Hartley) struggled to find his footing as a new dad to twins, co-parenting them with his ex, Madison (Caitlin Thompson), while dipping his toe back into the world of , the TV sitcom that made him famous.As he seemed to revert back to pre-fatherhood ways as he reintegrated himself into the Hollywood circuit amid preparations for the reboot, a not-so-innocent encounter with his 25-year-old co-star at a bar during a cast hangout and a video of one of his kids taking their first steps brought him much-needed perspective on where he stood in his life compared to only a few years ago. (Don't worry, no drinks for the recovering alcoholic.) So, Kevin — restless from the events of the evening — sent a text, «You up?,» to an unknown person.

We're to assume it was to his co-star, but this Kevin is a new Kevin. When the other person responded, almost immediately, with a simple, «Yes,» he decided to give them a call.Who was on the other end of the line?

Cassidy Sharp (played by Jennifer Morrison), the Marine veteran Kevin met at an Alcoholics Anonymous meeting in season 4, who also became good friends with Nicky. (Kevin and Cassidy also hooked up once, fueling many fan theories over the years that she could be the one Kevin ends up with in the end.)«Why are you calling me in the middle of the night?» Cassidy asks the second she picks up the call.«Because I'm sleeping on my sister's couch, even though I have enough money to buy a big, fancy house.

And because, Cassidy, I was about to call my 25-year-old co-star who plays my stepdaughter for a booty call and you live across the country and you were born before Y2K and I figured you were the better option.»Cassidy lets out a laugh before responding, «You.