Chyby (2021) - IMDb
Chyby: Directed by Jan Prusinovský. With Marta Dancingerová, Pavla Gajdosíková, Ivo Gogál, Eva Hacurová.
www.imdb.com
Czech melodrama about the difficulties in a relationship with a girl who previously starred in porn. The director filmed scenes that mimicked porn, so I think the short porn scene was shot using a stunt double, not using the porn available on the internet.
1:23 man masturbate while watching on woman 6:59 short porn watch scene