We got the longtime comedian leaving Nobu Tuesday night in WeHo where, at first, he weighed in on what had happened to Tiffany on New Year's Eve in Miami -- namely, miserably bombing onstage and cracking open some Ciroc to numb the pain.

He says NYE gigs are tough as it is 'cause everyone's already faded, and a night of partying for the comic themselves probably ain't the best idea if ya mix the two. Remember, Tiff had said earlier in the day that she'd been out all night raging before her set.

Then, Dave pivots to Louis ... saying comics always try new material with smaller crowds that aren't necessarily meant to be heard worldwide.

David sidesteps Louis' jokes -- like the Parkland massacre survivors -- he realized it's a hot potato.

It's worth noting ... Tiffany's tough night and Louis' tough night are dissimilar.