This will air before The Leap, which was 4.15 but is currently numberless. [On a related note, there's also been an update to those spoilers.]
The group spends an afternoon at Barney’s mom’s house. No sign of his brother James, but they do all get to meet Barney’s wife, Betty, and son, Tyler – momma’s boy that he is, Barney hired an actress to play his wife when his mother was on her deathbed, knowing that she didn’t want her sons to end up alone.
Of course, then his mother made a full recovery, and Betty’s been visiting his mother with him ever since. Unfortunately, the charade is ruined when Barney’s mom walks in on Ted and Barney’s fake wife making out, but when the truth comes out, she’s happy as long as he’s happy, and as long as he gives it a shot when he does find someone special. (Yes, there is a Barney/Robin moment here, reminiscent of the end of Miracles.)
Robin: She’s found a new job. It sounds like it’s the morning show equivalent of Metro News One – a little embarrassing and not what Robin imagined for herself, but she can at least take comfort in the knowledge that nobody watches it. Robin and Grant, the child actor playing Barney’s son, commiserate over the state of their careers as they approach milestone birthdays (Robin’s almost thirty, he’s almost ten).
Ted is pursuing the actress playing Barney’s wife, despite Barney’s warning that she’s crazy.
Seeing Barney’s “wife” and mother together, Lily and Marshall clash over Lily’s relationship with Marshall’s mother.