i don't recommend it, but i do have two adult males together right now. they had it out with eachother the second day of being together, nothing serious just some head butts, hissing, head bobs and tail slaps. since then they have been totally fine with eachother..they eat sleep and drink together.
but again, it's not something i would ever recommend and as soon as i have space available they are going to be sperated, i don't usualy like keeping more than 1 to a cage unless they are female..and even then problems may arise.