On an emotional level there is some merit to feel miffed by your oshi dating a huge femboy.
But even ignoring that viewers didn't turn into her content to play third wheel if her boyfriend managed to finnagle himself on stream ESPECIALLY if he's attempting to establish a career as an entertainer as well. People should be informed that they are playing third wheel if the people on stream are in a relationship. When Aethel and Nyanners announced they were dating they gave people the choice to tune out if they weren't comfortable with that, which is the right thing to do.
Life is lonely enough for many men out there, having it revealed that you were secretly peeking into someone elses relationship without your consent is genuinely cruel. Call me a unicorn.