"Also, if you begin the roll tightly around a length of string you can use it as a tampon for your bleeding vagina. Man-up, homeboy! You don't need toilet paper in the woods."
"Yes, really. And it's not a slight against women."
Where does the power of this insult come from if not in it's negative connotation of women? It's an insult that relies on the concept of women/vaginas being somehow weak, with the opposite positive value being strength, and only coming from men (clear in your use of the term 'man-up'). ie, 'don't be a weak woman, be a strong man'. That's the sexist (against both men and women) logic that exists behind your insult. Its equivalents are terms like 'pussy' or 'bitch', that are used as a derogatory term for someone who isn't as 'tough' as this culture's standards of masculinity require. Insults like this and the thinking/concepts behind them set us all up for harm. By saying your mother didn't use toilet paper either, you're saying she wasn't weak like a woman, she was strong like a man, but the same sexist logic is present.
There's nothing weak or gross about a woman or their wonderful bleeding vaginas (that you came falling out of no less); there's nothing wrong with a man if they don't live up to your standards of masculinity (or rather, the standards you've accepted). Gender roles and stereotypes suck.. they're damaging, and they're propped up every day by the things we say and how we behave (and the big one, media). I'm no saint either-- we're all born into this and it's a process of unlearning, but I felt it necessary to point out that sexism like that isn't OK anywhere, much less a mature forum like this.
Now don't get your panties in a bunch. (ba dum ch) (subtext: because if you show too much emotion and get a little frustrated you'll be acting like an emotional woman [who else wears panties?]! ...and that would just be terrible... right?......)