Marshall: [v.o.] And once I figured it out... I started doing crazy stuff to see how far you'd let me go.
[flashback to Marshall arriving at MacLaren's with a possum:]
Marshall: Hey, guys. This is Rex. He's a possum. I found him in the trash. He lives with us now.
Lily: I love him.
[present:]
Marshall: Lily, we are living with a possum. Rex is violent. And he hates us.
Lily: Baby, you just lost your dad. None of us wants to upset you.
Marshall: Please, if you guys really want me to get over the worst tragedy in my life... I'm begging you, tear me a new one. But not like Rex tried to in my sleep last night.