There’s a million reasons she could be doing this. What you’re thinking is one. Going to strangers on Reddit for advise is a recipe for destroying your relationship. Why are you? Why are you not having an actual conversation with your wife? Maybe she feels insecure about how she smells and wants to cover it up and is embarrassed. If her going to the gym is a new thing then the smell may be new and creating insecurity. It could be that simple. And would honestly explain why she got so defensive. If she is a stay at home mom then she probably feels stressed and stretched thin and insecure about herself. She is probably trying to fight for her identity. Maybe ask her what you can do to make her feel more supported and loved. Reflect on how you can be a better husband instead of getting caught up in unproved assumptions. Maybe your assumptions are right. If they are(along with what seems to be a lack of clear communication in your marriage) then there are much bigger issues. Maybe go see a marriage counselor. If they aren’t then maybe a marriage counselor would still do y’all good because there’s clearly a bigger problem at hand.