The wife sucks and fucks her husband for a bit. He puts a blindfold on her to spice it up. He fucks her in the blindfold and then tells her he needs to grab a towel. The switcharoo / swap happens and a stranger comes in and puts his dick in her mouth. He fucks her mouth for a bit and then he fucks her pussy bareback in missionary position. The husband gets some good close up shots.
At some point the husband tells his wife to take off her blindfold and she acts surprised to see a stranger fucking her instead. The stranger fucks her faster and ends up pulling out and cumming on her.
It’s clear that the wife knew the stranger was in there waiting for the blindfold to go on: she wasn’t that surprised and someone had to hold the camera while the husband had sex with her. Either way, it was a fun scenario.