Thisismyfun123 - Perverted

Your sister can be both relentless and quite persuasive, so you knew it was inevitable that eventually she would wear down your wife’s defenses and your wife would join your sister as a cuckolding spouse. 

"OK cucky -- but you'll have to do it into the toilet. I'll stand just outside the bathroom while you sit there and play with your little thing -- then be sure to flush it all away."

Top: you forgot your place and made a comment you immediately regretted, and from her “oh? Is that so?” reaction you knew you were in big trouble.

Middle: she turns and demands you follow her.

Bottom: pointing to the bedroom, she wordlessly commands you to go in. You bow your head and obey, and do what you know she expects. You’re already on the verge of tears as you drop your pants and panties to your ankles and assume the required position, bending over and resting your elbows on the bed, face down into the bed cover and brace yourself for her discipline.