Girlfriend accidentally turns you into cuckold after bet gone wrong

Your girlfriend walks into the living room and sits on the couch telling you about this jerk at work who thinks he is all that. She knows you are the best at fucking and tells you she wants to bet this guy that she can make him cum first. If she wins that guy will have to make a vacation for you two. It is a sure thing. You can even watch. The next day she has you in front of her and she is cocky and ready to win but as soon as he sticks his cock in your girlfriend's pussy her face tells the tale. He is huge and this was not expected. Still, she reassures you everything is okay. She tries not to like it and does some trash talking as she is getting pounded in doggystyle, but it is no use. As you sit watching her big tits sway while she is being drilled she starts to enjoy it and apologizes to you as she can't hold out any longer. She cums on his thick cock and the bet is lost. Accidentally, she has made you into a cuckold.