Mother-in-law incest, love, when it's time to shy away...

I currently live with my husband and step-son Keisuke. I am living a comfortable life with my kind husband who always takes care of me, but there is one thing that bothers me. It's that Keisuke doesn't smile at me... I tried my best to make him laugh every day, but as a result, Keisuke made a shocking confession.