When you suck his balls and squeeze his hairy nipples while your Nautical Engineering teacher gives a lecture on hydrodynamics on Zoom.
Dirty Silvia is usually performed in presence of cats and dogs often named Leslie
-Bro what were you doing this morning i could not reach you!
-sorry I was a bit busy doing Dirty Silvia to my parrot -oh sorry that's completely understandable man i hope you had a reserva especial 1906 bien fria afterwards, what a job
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.