I feel you, Bro. Been there and then been there again.... sigh.
After doing this for better than a decade, I have observed the following about SB's and allowance:
Once the cash is in her hands, she forgets about it. It no longer exists and she's already looking to you for the next gift. If you watch carefully you can actually see her put the bills in her purse with one hand quicker than a bouncer takes a tip at a Vegas strip club! Meanwhile the other hand is searching for more money.
You might as well have dropped all that cheddar in the garbage disposal in your kitchen sink. It can all be summarized by the phrase "what have you done for me lately?" where "lately" = the last 5 seconds.
It's not really conscious on her part. And it's not really an attempted scam. She just doesn't remember what happened. It's like when Ted Lasso told his star player to have a memory of a goldfish. That's your SB's memory - like a goldfish - 5 seconds.
About 5 years ago, I was dating one of my 1st porn stars. This is the 21-year-old blond who turned out to be bat-shit crazy. We had agreed on $500 per date with all access, BB and multiples. Totally unlimited and enthusiastic freak in bed. But - crazy. After tolerating much of her antics for far too long, here's what she did to make me bail out and pull the ripcord. She had me take her to a phone store to get a new phone. Her last one was lost/broken/stolen/shoved up someone's ass - the story kept changing. She asked me to pay for the new one, about $550 including paying off her past due bill. I told her I could use her allowance money to pay for the phone plus I'd cover the extra $50 as well. But she would get no cash for our date. She had the nerve to tell me that wasn't fair. And that she just couldn't have sex for "no money." I told her get into my car and that we'd discuss how to solve the problem while I drove to a "better store." I pulled up at her home and told her I was done. I had treated her with kindness, put up with her tantrums at 2 am and that it was time to go our separate ways. She was actually STUNNED! I had her exit my car and I drove off.
About 30 days later, she was run out of town and the porn industry for stealing from another girl on a porn set.
Life is good
The Cat