movie with a guy infected by a parasite who comes a meat-hungry horny monster. at the end he makes his house into a gooey nest and talks to his wife

When Seth Brundle makes a huge scientific and technological breakthrough in teleportation, he decides to test it on himself. Unbeknownst to him, a common housefly manages to get inside the device and the two become one.

Industrialist François Delambre is called late at night by his sister-in-law, Helene, who tells him that she has just killed her husband. Reluctant at first, she eventually explains to the police that he invented a matter transportation apparatus and, while experimenting on himself, a fly entered the chamber.