On Monday night, Adam Sandler returned to Jimmy Fallon’s “At Home” edition of The Tonight Show to duet with the late-night host on “Don’t Touch Grandma” — a song Sandler wrote about, well, not spreading COVID-19 to your grandma. “I love my grandma so much,” Fallon sings while strumming a guitar. “I know she loves me too.” “But thanks to this stupid virus,” Sandler cuts in, “there are some new grandma rules.” Fallon and Sandler suggest keeping it to Zoom, or “spending a quarter” to call your grandma on the phone instead. And besides, they sing, you can still smell her “grandma smell” from six feet away. Like the other late-night talk shows, The Tonight Show soundstage is shut down due to the ongoing coronavirus crisis and the need to maintain social distancing, so Fallon has been hosting the show via pre-recorded clips from his own home; celebrities like Sandler have been calling in remotely via video chat. Sandler previously made a guest appearance on Fallon’s “At Home,” where the duo discussed Saturday Night Live and Fallon’s impersonation of the actor. Sandler also debuted a brand-new song during that appearance, giving a shout-out to the doctors, nurses and other hospital workers who are doing all they can to fight this pandemic.