I am very sorry to hear about the breakup.

Especially when you'd already made plans to nurture their grandchildren.

I personally lean toward the open side when it comes to relationships. I won't two-time another out of respect for that person but I wouldn't be jealous of a significant other giving in to her humanity and exploring (and frankly wouldn't mind similar - if pre-agreed and done in a healthy fashion).

Of course flirting is a few notches below that in openness. Both flirting and 'looking' can serve as safety valves where the unfamiliar may be whiffed and possibilities fathomed.

Of course, looking at others (within reason) is no indication of a desire to leave a partner. There is more to a person than looks alone. As for flirting - well that was a missed opportunity for her then-partner to have a sincere heart-to-heart about what she finds desirable in that other person.

It might be that there is nothing special at all about the person flirted with - and that she just yearns for 'the hunt'. This realization could have opened new options between her and her partner - many of us are not fully open about our inclinations.

Even if there 'is' something about the person flirted with - and perhaps something that the partner cannot offer (examples: a full head of hair or intelligent conversation) - that could still benefit from some honest no-consequences conversation - and solutions could be found (such as determining that she lacks intellectual friends and that maybe embrace her having such friends as a means of diffusing any pent up desire for such - with the agreement that she would be happy with such an arrangement and could see herself remain happy with her partner.

Of course relationships are complex things. One cannot say for certain how their dynamic broke down. If things were toxic between them then they are fortunate to have broke up earlier rather than later - but I hope that lessons are carried forward.

As for you - your aspirations for grandchildren may have suffered a setback but no grandkids were harmed in the breaking of that relationship. They may yet be - The mother has yet to be determined. :c)

Take care (and if you want to stay in touch with her - its OK - but I do agree that there is only so much that a mother can reasonably intervene). @merej99.