
"yellow flag" in relationships is a subtle warning sign, like a character showing potential issues that aren't as severe as "red flags".
Found what someone posted before:
" because, at the start, i totally thought ml was going to be a Red flag. I was expecting cruel, manipulative, cold and demanding, i mean he kinda is all those, but only to people who deserve it. He's snappy but patient with mc and when he falls, he values mc's consent & cares for him greatly"
Bls wnere you had that kinda "oh this is totally gonna be a red flag... wait, why is it adorable?" thought when reading, or just where ml looks/acts like he wouldn't be anything good, but cherishes & values mc's feelings.
Yellow is just in the middle. You like a bit of toxic, but not where its psychological or physically torturing the other person. And the ml or mc can comeback from it without it being too excessive or dumbfounded.

You guys can try out my list some stories fit that: https://www.mangago.zone/home/mangalist/3253418/

here you go!! althought this is just a scramble list but most of them are what you describe ^^
https://www.mangago.zone/home/mangalist/2766786/?filter=&page=9
Not black flag or SA uke/bottom. Yellow flag or somehow green (to uke) when they fall in love.
Can also be obsessive uke.