I don't think she said anything about you wanting to know WHO he's talking to online.
She was saying-if they love each other and it's good-who cares if they are also previously exes?
Personally we DO have a WRITTEN boundary list. One of the rules is that we must identify to our primaries a potential PRIOR to dating them, and we have to identify and be sure our primary is ok with it before we move to relationships status.
That's strict to some people, but it works for us because as you said-we have small children in the house and we're all looking for stability and permanence.
BUT-if GG for example ran across his ex "new age girl", and they opted to date again; I'd be ok with that.
The key detail is that GG would NEVER keep it a secret from me (or her). We're mature, honest, open. If she "friended" him, he'd let me know. If he friended her, he'd let me know. If something started to develop, he'd let me know. If he wanted to date her again he'd let me know. He would expect her to respect our relationship...
Likewise with M, but I can't give you a name, cause he wouldn't consider his ex-wife for a variety of reasons that have little or nothing to do with me and everything to do with her current lifestyle and the damage she's done to their son. But I don't know any of the girls (except myself) from before her...
"Love As Thou Wilt"