How do you wear a speedo (swim brief)?
Put your legs through the holes, and pull the waistband up to your waist (hence the name). If you don’t want anyone to notice your bulge, wearing a Speedo is not the way to go. Unless your scrotum hangs down about a foot or so, consider your testicles to be self-tucking. I take it you are either posting this as a joke, or are a lifetime wearer of boxer-style underwear.