My best friend is huge. He can’t hide it as much as he tries. Sometimes I forward him links to underwear or swimsuits made for big men, but he never pursues them. He’s actually embarrassed to be so big. What a waste!
Funny, I do the same for my best friend. We're both well-endowed, but I've kind of become the subject matter expert on actually living with a huge penis day to day. I learned many years ago that I hated running—partially—because I needed a jockstrap to keep my dick from smashing my balls to bits. This eventually led me to thinking about my underwear in general, and I discovered underwear that were better equipped to handle my equipment.
As I said, my best friend and I are both well-endowed, but I recently realized that our needs are different when it comes to underwear. You see, I may have the bigger cock, especially when soft, but he's got huge nuts. I recently told him that he should be thinking about his massive balls when he's buying underwear, though I don't think he's heeded my advice just yet.
More relevant to your post, I understand the embarrassment your friend feels at having a huge cock. I also used to feel embarrassed. It's difficult to put into concise words, but society tends to be very good at making people feel weird about not being normal and making other people feel uncomfortable even when doing so is through no fault of your own. Being well-endowed ticks both of those boxes because, obviously, large endowments are out of the norm and people are so uncomfortable with sexuality, nudity, and their own bodies that anyone who presents "reminders" about any of the above is considered, at best, uncouth or, at worst, a pervert. At least, that has been my experience.