HB is a sexual act that defies description. It is so heinous that one is completely embarrassed by the mere mention of the act. Some have inferred that the "H" refers to hands, but the jury is still out on this. It is often done by members of the same sex or, in extreme cases, solo.
In order to further his career Marty A. allowed Dick C. to give him an "HB". He was sore for a week and never walked the same afterwards.