How is that heart Marshall? We can't blame him for getting it checked out.
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Barney has a vision in this scene from How I Met Your Mother. It's courtesy of the episode "A Change Of Heart."
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Robin dates a guy who acts like a dog on "A Change of Heart." That must be awkward.
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How I Met Your Mother Season 6 Episode 18 Quotes

Never screw over a girl whose last name ends in a vowel, because she's got brothers.

Barney

Lily: Ooo Barney's got feelings for a girl.
Barney: Yeah, penis feelings!