How can this be?

She wants something. Probably a place to live since she moved in so quick. Let me guess, she is unemployed and you make good money?

It does happen but it's usually not a good idea. Why rush into living together anyway?

Shouldn't you both take the time and work out if the dynamic that caused you to break up 20 yrs ago is still there?

I have done it a few times but not to rekindle a relationship, it was more about having sex.

The safer thing to do would be get out before you're in deep shit again. However, you have to decide if that's a risk you're willing to take, and if so hopefully it's worth it. Being that you've been divorced, I'm not sure how you can trust her.

Perhaps you both have matured enough and had enough relationships to manage the pitfalls before they become craters, but I'd certainly go very, very slowly.
I have no idea if the first break up was painful or mutually consensual, but most of us only remember the better things from long ago. Caution, Will Robinson, caution.

That is a perfect recipe for domestic abuse and disaster.

You should take this chance. Just be aware that the first flame that burned out should not be continued in this next spark. Travel, make different friends, and redo your house, this love is spontaneous and should be treated as such. It will only last if you live with this romance in the same spontaneous fashion as it begun. Take this chance, so long as she isn't abusive or draining psychologically i see no harm in building on this flame.

Don't do it. Don't ever go back to past girlfriends. It will end just like the first time.

She only ran back to you now because she made stupid decisions and wants an easy escape from her problems. But your job is to remind her that this door is closed. Thank her for the sex and kick her out. If she was the one who originally dumped you, then rub it in her face now as well.

You can't get back with your ex like that when it's over its over. It's only a matter of time when the same problems that caused the separation come back. Same shit different century.

I had a girl friend once. We were both 16 and we had an incredible amount of fun for 1½ years. By age 19, the fun had evaporated, and she dumped me. Thirty years later we met by chance. We were both unattached, and began dating again.

This time, we were both mature and different people than we were in our teens. The relationship deepened, but seemed to follow the same timetable. An incredible amount of fun for 1½ years. Then the fun slowly evaporated and we split up at the three year mark just like the first time.

The rhythms of life are more predictable than you would think.