Hatena no Hana

What would you do if you discovered your spouse had a secret stash of S&M equipment?
Youko is a housewife, married for 3 years to her husband, Jun. Things aren't great─Jun hasn't been sexually interested in her for over 6 months. She idly wonders what's lacking─would she feel more fulfilled if she had a job, a pet, or even a baby? Would any of that change things? During a minor spat, Youko slaps Jun. Initially mortified, she's met with an odd reaction.