Seperate them. You should never house 2 snakes together. They will compete for the same hotspot and hiding spot and simply over-stress each other. Boas do not need company - snakes aren't like most mammals that appreciate company. They will do fine, better even, if they are given the courtesy to live in seperate enclosures.
Also, the ONLY way to ensure these snakes won't breed is to seperate them.
Boas have also been known to eat other snakes, including other boas. This is a picture of what can happen when 2 snakes are kept together. These are ball pythons, but as I said, boas have the same propensity....
I'm not trying to belittle you - please understand, my concern is only for the snakes....