Vaejovis can be sexed by male pectines looking like /\ while females look like / \. So if you can look at them side-by-side, it should be fairly obvious if you have a pair.
If your "female" is stuffing itself like that, I'd wager a guess that it may be gravid. This, combined with the fact they're Vaejovis, would make me want to suggest not keeping them together. I've heard mixed reports of keeping this genus communally and my own attempts have ended in cannibalism.
If your emperor scorpion stops eating, don't panic.
Be nice -- you were a noob once, too
"Never ask an engineer to explain something, because he will."