Infidelity stings regardless of where the dirty deed is done, but when a spouse brings his paramour into the marriage bed, it is an affront that can rankle the sensibilities of even the most cynical judges.
In Michigan, fault is still taken into consideration in property and alimony awards. While adultery is not the scarlet-letter sin it once was, judges still consider this factor in fashioning property divisions. It can become even more damaging to the infidel if the affair resulted in dissipation of marital assets, or was so distracting that it affected his or her ability to parent.
The New York Times published an interesting article on the subject last month, and quoted several family lawyers, including one from Michigan. The bottom line professional opinion: having sex with your paramour in the marriage bed is not the smartest move. Adultery in some states (like Georgia) will result in an automatic bar of alimony for the cheating spouse (sorry, no such luck in Michigan).
The article can be found here. Wadler, Joyce, Don’t Try This at Home: Adultery in the Marital Bed, New York Times, Jan. 12, 2011 [Last accessed on Jan. 13, 2011]