Loathing is a strong word. She's more offended by his actions toward Korra, and in turn his inattentiveness in their own relationship. She's more disappointed than angry. I mean maybe they need a big discussion instead of one talking and other listening? I wouldn't use the word 'fight' per say but Mako can only say so much and accept that Asami is still hurting and needs room to deal with her own issues.