As Therm has mentioned, its best to separate the males from the females. This is the mos effective way to prevent breeding. Since your females are currently in the same cage together, you can probably have them in their own cage with no issues, but definitely keep an eye on them since they are both in breeding condition and hormonal.
If one of them happens to lay an egg, simply remove it. There is no need for her tin incubate it, and you shouldn't feel bad to throwing it away.