Ken, youc an't force your wife to be faithful to you by law, there are NO LAWS against cheating in most of the US and throughout canada...
This is left to be governed by church organizations, family therapiss, and by individual conscience.
I understand there are a few states that penalize a spouse for cheating in family court and such, but by and large romantic and sexual commitments to one's spouse are not enforceable by law...
Note I am not a lawyer, this is just the info I have gathered
Boundaries need to be managed by you here, not by the court.