Looking for info to disprove this stigma, I don't really have much other than one academic research paper I found but I don't think if the guy I'm arguing with would be willing to sit through and read that. He dismissed it as queer theory which he says has been "debunked" idk what the hell queer theory is. Anyway from what I can tell with this dude the simple and more obvious the better but it must also be backed by peer reviewed research
Just flip it around and point out that pedophilia is rampant among affluent cishet white guys to the extent that American culture for most of the 20th century heavily involved sexualizing young girls and normalizing middle aged men preying on them to the point that until relatively recently "suburban dad molests the babysitter" was a comedy trope. Point out that all the opposition to raising legal marriage ages come from white evangelical groups whose entire culture revolves around giving old men child brides.
The entire anti-lgbt thrust is just evangelicals and affluent cishet libertines projecting their own crimes onto their enemies even as they openly do the creepiest shit imaginable.
Unfortunately those labels don't apply to him really, he's Hispanic (second gen), previously heavily impoverished, and bi. He hates those groups as much as I do