I've done that , he was a guy I had been chatting to for a couple of years on the net, I had sent him some photos of her naked then I asked him if he wanted to fuck her, she didn't know I had sent her photos to him or that he was there to seduce her and she still doesn't, he met her with me present 4 times and when I felt she was ready he phoned her, it resulted in him fucking her for just over 4 years, she still doesn't know he was bait dangled in front of her, showed what an easy bitch she is though.