Based on the live, he would ask her questions and then either not believe her when she answered them or get upset when she didn't answer quickly enough.
"Do you have a boyfriend?"
"No, I'm single!"
"If you're single, why does it take you so long to reply? Obviously someone is keeping you busy!"
She alleged that this kept happening even though she explained that she can't respond to him instantly, all the time because she has thousands of subscribers across multiple platforms in addition to, "having to piss and shit and sleep and buy groceries," so eventually she got fed up when she blocked him on OnlyFans (and the screenshot Tittyluv3r shared seems to corroborate this) telling him to leave her alone. However, he didn't, and he showed up to her last cam show talking about her lying about having a boyfriend (or something close), which lead to her going on the rant.
If you haven't seen it, it wasn't a bad show. Especially if you think Ema is cute when she gets angry.