Damn poor thing. I feel bad for her cause I have a similar mindset based off the way I grew up but not that severe...or repulsive. However, I understand why you no longer want to be with her. That's tough.

This feels like a made up problem. Do you always draw the line on the specifics of dental hygiene routines? Just buy her a costco brand mega pack of floss and get on with your life.

While I can understand how that can be extremely off-putting, if you genuinely want to be with her, have you tried sitting down with her together and talking about it or offering to go with her to therapy? She's obviously extremely accustomed to a certain lifestyle and needs to learn that it's okay to spend just a tiny bit of money and that it's safe to do so. Not be willing to buy something for 98 cents at the cost of your hygiene isn't exactly a healthy behavior. I would suggest letting things calm down and slowly approach maybe trying to break some bad habits? Just my input. ♡ Best of luck, OP!

You said she grew up poor. Sometimes, those habits are very hard to break. When money is tight; and you have X amount of dollars, EVERY penny counts. And if that's the environment, she was raised in; survival becomes ingrained. A wasted penny, could be the difference between eating every night. It sounds like she could use a therapist; to help work through past trauma. And possibly; a couples counselor for the both of you. Not everyone has a place to call home, or the guarantee of a hot meal, every night.

I’m the opposite, I grew up poor due to my dad’s death but now that I can afford nice things, I splurge.

Yeah okay coming from an extremely poor and frugal person, that's not normal. The act of doing that or the act of flipping out. Even if she cleaned the floss. That's a disorder of some kind probably. Maybe ptsd from being poor even.