this is mostly true, and if you combined the sales of "milf" and straight guy focused lesbian porn, it'd probably eclipse the "barely legal" category

but it kind of negates that there's a lot of crossover, so... idk, I know we shouldn't get super judgey about what people fap to, but what does it say about heteromasculinity that these are the things they fap to the most. all three categories have the undercarriage of being about women that, in the real world, are not sexually available to you. she's either too young, gay, or implied to be involved with another man.