After Barney makes an out-of-place declaration that this is going to be a good night, Marshall reaches down and takes a pair of overalls out of his box of mementos, which is conveniently placed on the floor next to his booth at MacLaren's. It's so out of nowhere, I feel like there's a missing scene, but let's just go with it, okay? It's clear Marshall loves his overalls. He calls them "my jam." Robin needles him about being a virgin until he met Lily. Marshall and I find her comment unnecessary, but Lily allows that the overalls just might have been a dealbreaker. Laughing, Barney grabs the overalls from Marshall and says nobody could get laid wearing them. He then stops mid-chuckle and says (to himself, mind you), "Challenge accepted!" He's going to wear the overalls until he has sex with a woman. The gang rolls their eyes as he rushes off to change in the men's room. Robin says, "I actually dated that guy." Everyone makes regretful yeah, you did noises at her (and the writers) until Ted announces his Maggie game-plan. When she arrives, everyone should make nice with her for a moment and then take off. This is Ted's one shot at Maggie and he's determined not to screw it up. So, I guess we know Maggie's not the mother, huh?