Ben Stiller, Robert De Niro Play Michael Cohen and Robert Mueller on SNL

Ben Stiller and Robert De Niro did their best Michael Cohen and Special Counsel Robert Mueller on Saturday Night Live ... while also plugging their old comedy together.

Stiller played President Trump's embattled personal lawyer on SNL this weekend, and De Niro played Mueller ... who conducted a polygraph on the guy, just like their characters did in 2000's "Meet the Parents." The Byrnes and Focker jokes continued from there.

On a more seriously hilarious note, SNL threw haymakers at Cohen's predicament -- namely, getting raided by the FBI last week in relation to his $130,000 "hush money" payment to Stormy Daniels, among other things. They also went after Trump and his kids.