I recommend wearing underwear then. Most people actually do tend to wear underwear even when it isn't specifically only preventing a view of your testicles. A good pair of underwear can increase your comfort even when completely hidden under your clothes.
In that case I specifically recommend boxer briefs, they have the room you need to keep them healthy, but the tight legs necessary to keep them to yourself.
I recommend wearing underwear then. Most people actually do tend to wear underwear even when it isn't specifically only preventing a view of your testicles. A good pair of underwear can increase your comfort even when completely hidden under your clothes.
Even the best boxers can slip a nut out. As you get older those things get floppy.
In that case I specifically recommend boxer briefs, they have the room you need to keep them healthy, but the tight legs necessary to keep them to yourself.