Dating: Break up disclosure?

I know a couple who decided to take a break from their exclusive relationship.  The break only lasted 6 months but they dated other people. The guy hooked up with multliple women, including his ex-wife.  When the couple got back together, the girlfriend said she definitely did not want to know about his six months of freedom.  I was surprised because women usually want to know those kinds of things.  You know, to keep informed.

He wants to disclose everything.  He also wants to know what she was doing while they were apart.  If a couple is on “hiatus”, is it better to share the details of who they were seeing?  Would you want to know who or what your partner did while you were on a break?

I know a lot of couples who think some things are better left unsaid.  Do you agree?  Should some secrets be kept from your significant other?