I had an affair in a previous relationship toward the end of the nearly 10 years together. OVERALL I really regretted it. Not always but overall. I wish I had not done that and married the girl I was with at the time to be honest, we would have been together for life.

I've had a few relationships since that relationship ended as a result of that being found out. In my current relationship we've had our ups and downs and due to our arguments and such and each time we broke up either because I walked away out of frustration or she broke things off, from 30 minutes to 7 hours, we ended up getting back together...

But each time I moved further along with another option. First a number, then the next time it was a date, etc. Right now things are fine between my gf and I but I have told her she is so volatile that I can't be certain from one day to the next whether we will be together because she is so hot tempered. She has been working on a lot of things as have I to meet each others expectations for how we want to be treated though her hot temper is a bear to deal with and change.

Long story short, I had made plans with another woman during our last break up. I have kept postponing them since we are doing better currently. But I'm hesitant to give up the backup option though I can't keep rescheduling.

Furthermore, I'm supposed to have this other option over at my house and the stress of it all is a bit meh. I worry about my gf calling me and me not answering and her becoming suspicious, or me trying to answer and sneakily taking the call in another room but the other girl coming and saying something in the background.

My gf has a tendency to randomly call on some nights, more often than not, but not always. My friends told me they wouldn't let the other option go on account of how volatile my gf is. Not sure what to do. When we first started fooling around it was during the short periods of my gf breaking up with me over the stupidest arguments when she would get mad and end it then hang up on me, then calling me a few hours later to get back together.

I worry about having this other girl over because things are going well RIGHT NOW and I don't want to risk losing BOTH girls if my gf calls. Nor do I want to ignore her call and make it ok for her to not answer me when I call (though sometimes she does legitimately fall asleep when traveling).

But at the same time, I don't want to lose this other option as a backup because at my 40 year old age it's hard to find a woman who has never been married or is childless. That said, she's only been in one relationship 1.5 years, the other 3 were a few months because she said she saw they weren't compatible so she ended them. I find this to be hard to believe from a 35 year old woman unless there is something wrong with her and she's easily an 8.5.

My gf is a 10, but she is divorced and has kids which isn't ideal as I have no kids and prefer not to have kids. That said, my gf is a brilliant investor and I've been learning a bit from her so she has some value other than looks.

So what to do? Break it off with the other option?

Have her over anyways and figure out how to deal with any random phone calls from my gf?

Other options?