Do you know if he checks your social media?
My friend got divorced from a horrible man and we know he still checks up on what she is doing. We are both divorced so do quite a few things together, but we are by no means well off financially.
It started off when we visited a Buddhist temple for the day and she added the photos to her WhatsApp status. A few days later she heard via a mutual friend how "disgusting" she is for spending all HIS money on travelling overseas. Meanwhile we were about an hour away from where we live.
So we couldn't just leave it at that. So we go to local places that are other country themed and take photos just to post to piss him off. And we always have a photo taken together so he thinks we travelled together 😂
According to him we have now had great holiday on his expense to China, Italy and most recently, Greece 😂
The most ridiculous part is, he doesn't pay any CM anyway, and all my friend walked away with from that marriage was a car. Which she sold. And these are the funds we are apparently travelling the world on 😂
In fact just last night we were laughing about it and next month we are going to get AI to make us a photo of skydiving or something equally out there
But OP we too are petty, so I think you should spend that extra every month on something that you liked to do/eat, that he didn't.
I do love your persistence with this though.