Secondhand Dicktasting
The act of making out with a girl who is having sex with someone else on the regular, so by the transitive property, you have tasted his dick
Jon: "Mike did you make out with your ex-girlfriend again?"
Mike: "Yeah, why?"
Jon: "You are secondhand dicktasting her new boyfriend, how do you feel about that?"
Mike: "Yeah, why?"
Jon: "You are secondhand dicktasting her new boyfriend, how do you feel about that?"