After ad-libbing that he doesn't want his parents to get a divorce, "Tyler" manages to cry and run out of the room, impressing his formerly disappointed fake-dad with his improvisational skills. Meanwhile, Ted decides to work off the acting notes he's just gotten from Margaret -- which also include improvisation, as well as crafting rich back-stories for characters, making matters worse. The scene was such a turn-off, I can't bear to give you details. Suffice it to say he makes up a wild tale about Barney seducing Ted's blind fiancée years ago on a train to Monte Carlo. He then recalls Margaret's advice about not being afraid to get physical, and slaps Barney's face. Twice. Barney can't deal with everyone being off-book like this, so he encourages Loretta to give them some privacy. While Barney rips Ted a new one, Margaret is effusive with her praise of his mad acting skillzzzzz.
Barney is in a tizzy trying to figure out how he's going to explain any of this to his mother. Lily suggests it's time to tell his mother the truth. Marshall's still angry about Lily's earlier admission. "I don't know, Lily. Sometimes, honesty leads people to say mean things about a woman who always took special care of me because I was the runt of the family." Realizing his friends are looking (up) at him, Marshall adds, "For crying out loud, I'm only six-four!" He storms out of the kitchen and we SIDEWAYS SLIDE to...
The front porch: Grant is reveling in his big emotional moment. Robin reminds him that even though he hates the gig, he loves his craft. He says maybe that's how it will be for Robin at her new job. She thanks him, tells him he's pretty smart, and gives him a friendly squeeze. When she pulls away, he lifts his head and puckers his lips, just waiting for a big smoocheroo. Robin yells, "Whoa, whoa," and Grant remembers himself. Waving his hand, he says, "Sorry. Sorry. Thought I was picking up on something." Remember where I said he's supposed to be six? Yeah. Right.
Cut to Loretta's living room. Barney walks in, and she asks him if he's okay. He tells her there's something he should have told her a long time ago, and then says, "Tyler is dying, and Betty said when he goes, she's going to off herself. So that's probably all gonna go down pretty soon." He stops himself, though, once he realizes how he's alarmed Loretta, and comes clean about hiring Margaret and Grant to play his family, saying that he just wanted her to think he had the life she wanted for him -- that he wanted her to be proud of him.