Several of the scenes involving Abby and/or David in Nobody Likes Babies, but the one where David charges in and accuses Abby of stealing an important piece of his evidence, his voice cracking as he says he trusted her because she said she loved him takes the cake. Especially when she insists she does, and he refuses to let her touch him.
Fitz: Did I do this to you? Or have you always been like this? Because if it was me, I'm sorry. I'm sorry.