Even a rock solid partnership will experience some growing pains when one partner makes such a big life change. Now that you're not both clocking in, it can be harder for whoever is still working to relate to what life is like for the one at home. Each party might have different expectations for how responsibilities are divided. Or the SAHM might just carry most of the weight at home like they did when they were working, just with less added stress (amirite?!). It's not necessarily negative, but it's a transition.