From my casual research over the years, if you don’t like someone’s natural body odor your immune systems are incompatible with each other. Before we started covering up our natural smells with frequent bathing and perfumes, smell selection was an important part of mate selection. Now that we mask our scent, it’s possible to select a mate that we are biologically incompatible with. One of the things I first noticed about my wife when we were dating is that I love her natural body odor. I love when she doesn’t shower on the weekend. Likewise, she loves my natural body odor and will ask me to postpone showering or putting on deodorant so she can get more of it. I’ve been with partners whose natural body odor repulsed me. I couldn’t stand their smell nor the smell of their clothing after they had worn it. Maybe we should take more opportunities to smell the natural body odor of potential partners and rule out those who don’t smell good.