I personally don't use it like that for multiple reasons. I don't think "gay" should be used as an insult and I just don't think "your mom" jokes are funny. However, there is a difference in who says it. Just like there are people of color using the N-word amongst each other because they either use it ironically or just in a form of protest against the "white use" of the word, there are women calling each other the b-word endearingly, left-leaning Germans calling each others Nazis ironically, etc. And just the same there are gay people calling each other or themselves the f-word or say things like "ur mom gey" in a similar fashion. Look around on this stream. Though somewhat rare, there is the occasional joke involving someone being called gay as an insult or using other homophobic or transphobic slurs as a punchline or saying things like Apache attack helicopter or - more recently - tax evasion is a gender. It is a difference if you use it as an actual insult or ironically/sarcastically knowing exactly what it means. It can be very hard to tell your intentions online without any form of non-verbal communication so usually people will react based on what they know about you or, even more defensively, based on your username or the fact that you just haven't "proved" you're "allowed" to make a joke like that. I know it can be very confusing which is why I usually only make jokes like that when I'm pretty certain of a person's reaction. I like very dark humor but I also know not everyone else does and in some cases words can hurt, even if they have used the same words themselves. It's always important to keep that in mind.
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