A person who completely controls their significant other into doing whatever they want...
...generally hated by all of the significant other's friends.
Guy 1: What happened to Mike? He used to be so cool, but now we never see him.
Guy 2: Yeah, that's because he does whatever his Cuntriloquist tells him to do.
Guy 1: That's true. Karen is such a bitch.
Somebody who is able to make a lady sing through the art of Cunnilingus
"I went out on a date with that bird from the pub last night. It went really well and by the end of the night, I turned into a proper cuntriloquist! I tell ya, she was singing in tune dude!