I'm honestly under the impression that they never dated, it was a marketing ploy to sell more sets/patreons because separate, they were both pretty mid back in the hey day of cosplayers but "HURR DURR LEZBEENS" does things to a coomer's neurons so they made it big. It was just that in the end, SuSu made something of her self but Bunny fell behind, tried to bully her way into a few more communities and got btfo'd out of them.
Calling them mid is laughable. Bunny isn’t looking her best these days but back then she was very cute. SwimsuitSuccubus was the most popular lewd model at the time. She was basically the Belle Delphine of her era without all the controversies and weird shit. Susu didn’t need Bunny at all to do well and Bunny was a nobody until she dated Susu.
Susu was popular but I think calling her the most popular one is a bit of a stretch.
Susu did went to cons with Momokun and Bishoujomom and they did promos together. I remember pics of them in those situations, taking pics on kinda ugly hotel rooms. This was very early though, and people were mostly making fun of them because of what I said. They didn't even pretend to cosplay anymore.