This man is the father of Sammy, Sal's son.
He is mentioned when Sal, the mother of his son went to see him because he was unaware of Sammy's existence. It turned out he's married so he was out.
Sal felt stressed since she found it so hard to raise her child and was guilty that he didn't have a dad in the picture and she wished she could give him one and Cam, Mitchell, Pepper and Ronaldo all offer to be fathers to Sammy and would always be there for Sal whatever she needs and assure her that she and Sammy will never be alone which makes her happy and she tells the guys that they're so sweet.