Males will fight during the breeding season. They do this by winding around one another's bodies, and throwing each other around. Fascinating to watch, but not a situation where you would want the poor loser to be forced to share space with the winner afterward. This would be very stressful for the snakes.
Other reasons NOT to do it:
If one snake becomes ill, the other is more likely to contract the same illness.
If one snake develops a problem such as a failure to defecate or urinate, or diarrhea, it can be difficult to tell which snake is having the problem.
Snakes may compete for hiding spaces and heat, forcing one snake to give up the most desireable spaces. This is unfair to the loser. It deserves better in your care than that.
Although it is extremely rare, do not think for one moment that ball pythons NEVER eat each other. I have heard a reliable eyewitness account of it happening.
If your problem is that you cannot afford another tank, and do not have space for it, then you CANNOT AFFORD ANOTHER SNAKE. Stop trying to justify it, and accept it. Wait until you CAN afford a second cage, or even a small rack, before you acquire more animals.
