Bored and horny, I seize the opportunity while my wife is out, sneaking into the bathroom to pleasure my sister-in-law. With the door locked, I lift her skirt, revealing her wet panties. I pull them aside, diving in to taste her sweet cunny. She gasps, trying to stay quiet as I feast, her hips bucking against my face. Just as I feel her about to cum, we hear the front door open. Panicked, we quickly adjust our clothes, hoping my wife didn't hear her sister's ecstatic moans.