Of course toxic masculinity is a thing. Ever heard that “real men don’t cry”? Ever felt like crying, and forced yourself to stop because you don’t want people to think you’re not manly? That’s toxic masculinity. It’s a set of unfair, unreasonable, unrealistic expectations of what a ‘real man’ should be, expectations that fuck you up when you try to live up to them.
You see a lot of it in porn. All the ‘forced cocksucking’ and ‘forced feminization’ stuff is all a coping mechanism for toxic masculinity, bisexual men finding ways to express a side of themselves that the “rules” of masculinity say is abhorrent and shameful. Heck, even the “Real Men Don’t Eat Quiche” stuff is about toxic masculinity, although I’m not sure whether it’s an example of it or a parody of it.
Basically, whenever common sense is telling you to do one thing, and the ‘Guy Code’ is telling you to do another, your brain is being poisoned by toxic masculinity. And that shit kills.