Ok, movi is about a couple with kids, that have a beautiful life, but im some point they got bored and desided to have a sex with another couple that us sick. They recorded the sex that they had and the guy started with blackmail. He was everywhere, at their work, at house like buying Tv for kids everything. I remember that at the end of movu normal family couple wanted to kill them, but sick couple had an accident, and they instead of helping them they throw on matches and car exploded. It is great movie but
I can no remember any actor. And it is pretty old movi, I wipl say nineties or maybe a little later..but Its old.