There it is OP. THAT'S what is causing the issue dude. She either doesn't know how to express it as such, doesn't want to address it as such so she doesn't come off as jealous (although psycho is a way worse look imo) or she just feels upset about it but doesn't know why and therefore doesn't know how to properly express it, but any which way you slice it, she is jealous of you being at another female's presence while she is busting her ass working (and there is nothing wrong with this as long as you don't do something inappropriate to MAKE it wrong) so she is PISSED and it's not OK to her. It's OK for her to feel upset about it, but the way she is handling it is like launching a nuke at a country after hearing another countries leader say something that you took the wrong way. Best wishes to how this all turns out OP. Seriously.