It was the worst winter storm in recent memory. The sub-zero temperatures mixed with the near constant snow had ice building up on power lines and knocking out power all over the city. Including my house. My mother-in-law was much luckier, when we called her to let her know we lost power, she told us she hadn't. My wife and I made the decision to brave the horrible traffic and try to make it to her place.
It wasn't easy to quickly pack a weeks worth of clothes and supplies for two adults and a two year old, but we somehow managed to maneuver around a dark and cold apartment using the flashlight app on our cellphones to get everything ready. We (meaning me) then had to manage to get everything (two suitcases and a car seat with a fussy and upset baby) into the car and out onto the nearly impassable roads. The city was doing it's best to keep the roads clear, but what was normally a twenty minute drive took nearly two hours.
"Thank you so much, mom." my wife, Fiona said when we were finally settled in.
"Of course. I know you would do the same for me." my mother-in-law, Kate said.
"It's bad out there," I said, "According to the radio, over 1,000 people have lost power, and at least twice that many are predicted to be out by tomorrow. It's fuckin' bad."
"Mike!" my wife said, gesturing to our son, who was busy chewing on his fingers.
"What? He's barely two years old." I said, "He's not even paying attention to me, he's trying to eat his hands."
We were off our normal schedules because going to work was not an option, so we took advantage of the time to sleep in. I woke up late one morning (around 10, which is late for me) and decided to take a shower. Now I should state that the upstairs of Kate's house has two bedrooms, connected by a central bathroom, which is only accessible from either the master bedroom or the guest room, where Fiona, the baby and I slept. There was no entrance from the hallway. I could hear the TV playing downstairs and my son babbling along to whatever cartoon he was watching, and I was guessing my wife was on the couch reading or watching along with him.
After making sure the bathroom was clear, I took a quick shower. As I stepped out and started to dry myself off the other door opened and my mother-in-law stepped into the bathroom apparently having just woke up herself. She must not have heard the shower running when I was in there. For a moment we were both frozen in place. Me with just the towel in my hands as I was about to hang it back up and get dressed and Kate standing there with her robe half open with nothing on underneath it.
To this day I don't know what came over me, maybe it was the sight of my mother-in-law's tits through the half opened robe, maybe it was her eyes glued to my rapidly hardening cock, maybe it was unbridled lust, or maybe it was the impulsive "act first, think second" mode my brain sometimes went into. Maybe it was all of the above at once, but whatever it was, I crossed the bathroom, pulled my mother-in-law inside, closed the bedroom door, bent her over the counter and shoved my cock into her without a second thought.
"Oh!" was all Kate said as I slid all the way inside her and started fucking her for all I was worth as my wife and son were watching TV right below me.
"What the hell am I doing?" A little voice inside my head said, "What's wrong with me? This is my mother-in-law! I shouldn't be doing this!"
"But it feels so damn good!" Another voice said. Ah, yes, the angel on one shoulder and the devil on the other. Neither voice stopped my hips from pumping my hard cock into Kate's warm pussy. "Almost as good as my wife. And she hasn't tried to stop me yet."
"Probably because she's still in shock over what I'm doing." the angel said, "Look at her!"
I tore my eyes away from the sight of my cock sliding in and out of her to catch her glance in the mirror. She was looking at me with the same "Fuck me" look that my wife got when I fucked her. She wasn't trying to stop me because she was enjoying this as much as I was!
I turned my attention back to my cock sliding in and out of her. Nothing was said, and the only sound was the sound of my hips slamming into her ass cheeks as I picked up the pace when I realized she wasn't going to stop me.
She leaned up and pulled the robe off and tossed it off to the side. I took that moment to slide my hands around to her magnificent double D-cup tits. Just like my wife, Kate had more than a handful of tit flesh to grab onto, but if I could handle my wife's tits, I could handle her mother's monsters. I gently squeezed and pinched her hard nipples as I continued to slide my hard cock in and out of the same pussy my wife had emerged from nearly 40 years earlier. The fact that I was fucking my 70 year old mother-in-law in her bathroom while my wife was just below us made it all the more exciting. I swear my cock got harder than it already was.
Our eyes met in the mirror again and Kate smiled at me and started pushing her hips back at me as I slammed into her. Keeping one hand on one of her huge tits I reached down with my other hand and started rubbing her clit, she closed her eyes and bit her bottom lip letting out a soft moan. I had lost track of the time as I stood there fucking my mother-in-law, but I knew it couldn't have been more than a few minutes before Kate said the first thing either of us had said since we started. "Oh God... Mike... I... I'm gonna..."
A moment later she covered her mouth and moaned low in her throat as an orgasm tore through her body. I grabbed her hips as her body tensed up and she let out a shuddering breath as her orgasm ran its course. Holy shit, I just made my mother-in-law cum! That coupled with the fact that my wife and son were oblivious to what was going on just above their heads bought me to the point of no return and I could feel my own orgasm approaching.
"Oh shit, mom..." I called her mom, because Kate felt too formal, "I'm gonna cum."
I exploded inside her a moment later, shoving my cock all the way inside her shooting jet after jet of cum deep inside her. "Holy fuck..." I moaned as I felt the last spasm run through me and into her. Kate clamped her pussy tight on me and stared at me with lust in her eyes in the mirror. I reached around and grabbed her large melons one last time, flicking my fingers across her nipples.
I felt my cock start to go limp and slowly slid out of her. Neither one of us bothered to cover up as she turned around and leaned against the counter, now looking me in the eye face to face.
"I'm sorry, I don't know what came over me." I finally said after a long moment of running my eyes over her body.
"Don't apologize, that was the first time since the divorce from Fiona's dad that I've been fucked. It's been over ten years." This was the first time I'd ever heard Kate swear. "But as good as that felt, we can NEVER do this again. Not that I didn't enjoy it. I did, I really did, but you're my son-in-law, you should be saving that for my daughter."
"I understand." I said, "You're right though, it did feel damn good." I took one last glance at her naked body, which she had still made no effort to cover.
"I'll always remember this, and I know you will too." she said.
I just smiled and nodded before leaving her to take her shower.
A couple of days later the storm broke and the city was able to clear the roads and started restoring power. Once we got news that our area had power restored, I packed up the family and headed back home. Kate kept her promise and we haven't had any further sexual encounters since. But every now and then at family gatherings we'll make eye contact and smile at each other, remembering that one winter morning in her bathroom where we turned up the heat.