Mr Marc was gay and into young boys. In the documentary IIRC he said sometimes he would see a little boy and wished he could fuck him in the ass but he rather had a huge freaky looking dick than a few moments of ofrgasm. This means he mostly did anal and oral and therefore he is out of luck performing any penetration.
He was obsessing over another guy that had a 22" circumference girth and his goal at first was to be the same but then he decided he wanted to be bigger after he reached his goal. I think he also injected his lips.
I got to get my nut or there is no reason to have a penis imo. Why walk around with a huge monster cock that can't pleasure your partner or yourself? I mean it's great to be a freak of nature but look at people Johan Fallan who has the world's largest penis and he looks like a complete lunatic. I'm pretty sure people are creeped out just talking to him.