It's the monkey in the branch analogy:

She wants to make sure the "branch" she's jumping on now won't break, so she continues to hold onto you "just in case."

(fyi, a 19 year-old branch is definitely going to break)

She knows you won't break. Why? you've proven it over, and over, and over again.

If you want change for both yourself and your R, you need to break the branch and take away her safety.

Everything WW just relayed to you falls under either
A: temp-checking,
or
B: Seed planting manipulation.

She wants you to tell her you're ready to start dating so she doesn't have to feel bad about what she's doing to you. She literally thinks that she will be able to continue to have the sex with the young buck and you will be there for the rest of the R stuff

She clearly doesn't want to kick you to the curb; she wants to keep you around and still do whatever else she feels like and you're letting her.

When you are truly ready to "drop the rope" or, in my previous analogy, "break your branch," that is when you will truly start to see positive change for yourself, which needs to be where your focus is right now

If you want to know what that looks like on her end, I'll tell you:

1: You drop the rope (If it's me, I call her out right there about the A and let her sit in her own S**t)

2: She does 1 of 2 things:
A: has a complete meltdown; begs for you back right off the bat. You start going from there because now you guys are on even ground.

B: Has a complete meltdown, runs to 19yo.

He just wants one thing (remember being 19?) which is why they are together. You are the R piece still, and you are gone, so now he has to pick up all the rest of the stuff, which he doesn't want to do.

Things fall apart around her and she either comes crawling back to you (you've been working on becoming a man only a fool would leave) or jumps to the next branch (not your circus, not your monkey, not your problem).

Goal with a WW is that YOU take care of YOU first. She's trying to let you down gently, but it's not for you. It's so she doesn't have to feel like garbage about what she did. She'll try to throw it back in your face, telling you that it's your fault or some other excuse, but she's a big girl and she knows right from wrong and you tell her that!

Remember: being cheated on is never the LBS's fault. It's not on you, man, It's on her! The R getting to this point might be on both of you, but the A, that's her burden to bear.