The act of pleasuring your partner sexually with little to no reciprocation. All attention and pleasure is devoted to the person being serviced, as opposed to it being more of a give/take situation. This term is more common in the LGBT community, and is often favored by more submissive partners who enjoy pleasuring others more than receiving.
A George Carlin term for the act of a salesperson screwing over their customer through deceit. This is catagorized by the large bullshit smile, and customer assuming the position.