Karma is a Sanskrit word that means “action”, or “deed”. It is commonly associated with the idea of a cosmic cause and effect law, where whatever action is taken in life it is repaid back in kind in this life or in the next ones. Thus, when Michael Vegas replies a neighbor’s call for assistance he should be generating an equal reaction in kind.
However, the kind of Karma he gets back is not what he would expect, as it takes the big-boobed shape of Karma Rx, who tricked him in the first place with a fake distress call just to knock him out and abuse his ass with a massive dildo. So long as he enjoys that, this qualifies as good Karma as well!