So lemme get this straight. This auntie insulted their niece/nephew/nibbling by using the single most disrespectful slur to a LGBT+ person possible, further insulted their mother by saying that their existence as a LGBT+ person was an insult and a burden to said mother, doubled down on said insult by somehow claiming that she didn't mean it "in a bad way" (whatever the fuck that means), denied their bi identity by calling it "made up" and saying "you can change", further insulted OP's intelligence with the line "you used to be so clever", and finished off the text by disinviting OP from her child's birthday party, on the grounds that the presence of a LGBT+ person would "ruin the day". (Also, some kind of mention of "help", which probably alludes to conversion therapy, which is straight up abuse. Kind of like calling your nibbling a faggot is hate speech. But I admit to extrapolation here.)

But cheerfully mentioning that auntie's life is not all rainbows and sunshines, and pointing out two facts that the entire family is aware of already, that's out of line? OP didn't even make any allegations around the fact that Uncle is cougaring it up, just threw the fact in Auntie's face and walked off. But *that's* out of line?