...I'm not thinking like you about the reasons why some people (not only women...) would prefer that there partner won't have outside affairs.... That's a question of Love...and to think that your lover should a priory, desire you...and be intimate with you...
If the sex is inexistant between 2 people of a couple, they are in crisis, and they should find a solution...
A real equilibrate couple share an equilibre exchange between their heads, theirs hearts and theirs body's need... and in this situation, why someone would need to go outside their relationship if they are already all fullfilled???.........