Her Cheating on You May Mean She May Still Get Alimony

The Tennessee Supreme Court, along with the blessings of the Tennessee Legislature, has seen fit to essentially ignore any betrayal she may have committed which resulted in your divorce.  That is correct, when it comes to making you an alimony slave, her behavior prior to the divorce is practically ignored.  

“The two most important factors a trial court must consider are the need of the disadvantaged spouse and the obligor spouse’s ability to pay.”
Mimms v. Mimms, 234S.W.3d 634, 638 (Tenn. Ct. App. 2007) (citing Bratton v. Bratton, 136 S.W.3d 595, 604 (Tenn. 2004)). 
Source

Way down on the list (#11) of factors to be considered is:

(11) "The relative fault of the parties in cases where the court, in its discretion, deems it appropriate to do so..." Source

Notice the little clause "in its discretion"  That means the judge can simply ignore anything she has done!

In conclusion, the system wants to make you the worker bee, her the queen bee, and consider your hard work as the only relevant factor.