Mom mistakenly grabbed her son's dick and paid for it

I take a risk, but I hide my naked sister under the blanket so my mom won't notice

"Sonny, do you want your mother to make you feel good, tell me honestly?"

Son, what are you hiding under the blanket? What's so hard under there?

"Daddy, let me be in Mommy's place. You'll see, I can do it!"