@bob79,
I suspect I do not have to tell you that you are, as they say, playing with fire.
And it's not too much of a limb for me to go out on to deduce that you have not told your partner anything -- or at least not everything.
I have old flames on Facebook (a few are still single, or single again), and even one where the breakup was not a thing either of us had wanted but the difference is -- I ain't having these feelings. I am telling you this not to toot my own horn but rather to point out: these kinds of circumstances can happen and, in fact, they may not be rare at all. And certainly getting cold feet before getting married (particularly to someone you have been with so long that the thrill may be gone or wearing off) is not atypical.
It does not mean you have to act on anything. It does not mean you have to obsess about anything.
If you are tired of your partner and do not wish to wed, that is one thing, and that should be wholly independent of the deal (whether there really is one or not) with the old flame. E. g. if Suzy is the old flame and Mary is your current squeeze, any issues you have with Mary have to be Suzy-independent. Did your issues with Mary predate those your getting reaquainted with Suzy? Or did they surface
because of Suzy?
You have children and they are minors, so Mary will never be truly out of your life, whether or not you and Suzy ride off into the sunset together. You need to work out custody and payments and whatnot. You cannot just shed Mary and expect to have everything be hunky dory with your kids. You don't say whether Suzy is married, has any children, etc. Perhaps those complications exist for her as well. So then it's is Suzy's husband, and her children, who are in this mix as well.
That's a lotta people to be involved in this.
Anyway, I'm rambling.
Bottom line:
- this is trouble.
- cold feet are normal and people can have all sorts of weird thoughts before a long-anticipated wedding. This does not necessarily mean that the wedding should be called off.
- clean your own house first (e. g. end things with Mary, if that's what you truly desire) before making a new one (e. g. taking up with Suzy).
- recognize that your children, and Mary, will be involved no matter what. Not only do their feelings matter here, but so do their economic needs. Your kids need to be fed, housed and schooled no matter what. Mary needs to have a home no matter what and will undoubtedly have at least shared responsibility for the children. It will suck a lot more if she is constantly angry with you about how things ended versus a more amicable split -- and your children will bear the brunt of those ill feelings.
- recognize that this is not the first time that Facebook has stirred up this kinda stuff, and it won't be the last.
- Suzy has changed, and so have you. You have not remained in a time capsule, fresh and young, and neither has she. Your memories of a decade ago (and hers) are probably nowhere near being accurate, even if the two of you confirm them.
- Finally, think about what it will be like to start from scratch and be lonely, in case the whole Suzy thing never takes off. For that is a very real possibility as well. How will you live? How will your children?
Me, I wouldn't risk it. Have I been in touch with flames? Absolutely, there are very few who I truly would not be friends with now. But risk my marriage for 'em? Yeesh, no. Things end for a reason.