Like Chilli said, keeping two males together is fine and most seem to get along just dandy. One thing I need to point out though are dominance issues. At around 7 to 9 months males begin to mature, so you need to watch them closely during this time to make sure they don't start showing aggressive tendencies. It is common for males that have always gotten along to start spatting around this age, and sometimes, though very rarely they need to be separated or neutered to control their hormonal aggression.

Luckily, in my whole almost 10 years as a breeder I have only had about 3 bucks turn aggressive at this time. I've been very lucky.

Chilli, where did you get your boys pictured? Were their parents both rex? The reason I ask is they look like hairless to me. A lot of hairless have hair on the face, paws, and butt. Their whiskers are very different from double rexes. Their whiskers are tightly curled and closer to the muzzle, whereas double rexes have long curly whiskers.