My bro and sis-in-law had been exhibiting odd behavior for a couple of weeks prior. Every conversation they had was becoming more and more intimate. On that fateful day when they thought no one was around, they started to engage in an incestuous encounter. Little did they know, my mother was right there in the room! Our embarrassment was clear, with no escape in sight and our erections exposed in our underwear. Thankfully my mom was understanding of the situation and decided to teach them a lesson in proper incest sex.