Did this hotshot homewrecker hog down the horny Hankins housewife? I still think the signs point to yes, or at least Brian should be suspicious.
I think that's why Brian is going on and on about this LSAT business. She probably comes home from her days with Stein invigorated, he probably tells her tales of big cases won and lost, introduces her to important people, and makes her, herself, feel needed. Then she comes home to Brian, a man that probably discusses deadlifts at the dinner table, and he can see the disappointment in her eyes.
So Brian needs to become a barrister in the hope of rekindling something, but Em's lost that loving feeling, and now it's gone, gone, gone.....