Fellatio
This is an Italian film ad for Devil in the Flesh, directed by the great Marco Bellocchio in 1986. It was one of the first mainstream Italian movies to show actual unsimulated fellatio (in one extended sex scene between Maruschka Detmers and Federico Pitzalis.) I think honors for the first engorgement go to the infamous 1979 Caligula. Devil was later issued on video in the U.S. in both X-rated and R-rated versions.