Jimmy Fallon is getting used to the idea of allowing celebrity guest comedians to “tag in” for his monologues on The Tonight Show. On Wednesday night’s show, Fallon invited Billy Crystal to add several tags on a series of jokes about how old presidential candidates Bernie Sanders and Hillary Clinton are. Bonus points for noticing Fallon slip into an impersonation of Crystal’s “old man” voice.

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Billy Crystal sits in conversation with David Steinberg tonight at Town Hall as part of the New York Comedy Festival.