[TOMT] [MOVIE] [2000’s-ish] slasher about a woman with no head no its not sleepy hollow, or headhunter

There’s this movie I watched when I was a little kid that I absolutely loved. It was like a early 2000’s slasher about this woman who seduced her coworker but she actually ended up being like a headless zombie thingy? I can’t remember the name, or who even starred in it since I was about 9 or 10. I think the guy the headless woman is seducing has a gf and the movie ends with the gf not having a head and screaming at him. There’s a scene where a woman loses her ring down a garbage disposal and when she tries to get it it turns on. Ive googled it about 30 times now and I can’t find anything pls help I literally made a reddit account for this

[TOMT] [MOVIE] [2000’s-ish] slasher about a woman with no head no its not sleepy hollow, or headhunter