Reddit mentions of Calvin Klein Men's Steel Micro Low Rise Trunks, Black, Medium

Boxer-briefs or trunks with enough support.

I personally use Calvin Klein Men's Steel Micro Low Rise Trunk. They have plenty of support (for both your penis/testicles and butt) and they contain everything very neatly. I don't personally consider myself very big, however I am usually 4-5" flaccid. Them being low rise trunks is just a personal preference, I don't like "long" underwear.

If you like the trunks, I've also used Calvin Klein's CK One Micro Low Rise Trunk before, however the pouch was nowhere near big enough for me, and the leg openings were a bit too tight.

Might be a good idea to buy a single pair first to see what you like, and what's most comfortable for you. I made the mistake of buying 3 in one go. I still use the CK One's, but strictly as backup when my Steel Micro's are in need of a wash.

This all day long. I swear by the CK Steel Micro Trunk. I can't stand the longer legs on other boxer briefs, and these things fit like a glove (size down), don't ever smell, and last forever. Great colors too, if you're into that sort of thing.

Just make sure you get the "Steel Micro" because they make other styles out of cotton that aren't even close to the same quality.

I wear trunks they have like 2 inch inseam? just short enough to fit under most short shorts. Briefs are also an option.

I have these. They are nylon and CK brand so a bit pricey but sometimes they go for $12-15 on amazon, I have found them for $8 at Marshalls. They are incredibly soft and feel amazing. Even wearing skintight leggings nothing shows up. but that might be a case by case basis since my junk is not that big in the first place. Well I feel like those undies pouch area prevents any bits from being outlined.
Trunks
https://www.amazon.com/Calvin-Klein-Underwear-Trunks-Medium/dp/B000TGWFLC
Briefs
https://www.amazon.com/Calvin-Klein-Strength-Micro-Medium/dp/B015O3XNAQ/