Gathering my thoughts and not wanting to contemplate what had occurred I went to the bathroom and turned the hot tap on. I at all times put full hot on them top up with cold. As I turned to leave something caught my eye that opened another Avenue of my MIL’s stay. A pair of panties. These definitely were not Karen’s, they were a different size and style to what she at all times wore. They were French knickers, I’d at all times loved these but Karen doesn’t like them. She’s strictly thongs or commando, I wonder if Susan is going commando now. As the water was rising I had to stop and think why were they there? Susan was playing the provocatrix. She’s clearly had a bit of wine and it’s gone to her head. Inquisition got the better of me and I had to look closer. The door to the bath room was closed so I had no worry of being seen. These panties were drenched! That cold woman I knew for years was actually………..attracted to me? “No” I wondered, it can’t be. They must be Karen’s and she’s being filthy.

Having convinced myself I went and got changed. I could hear the women chatting away downstairs, the conversation had lightened and laughter was emanating from the kitchen. The whole situation had gotten to me. I wondered “should I walk from mine and Karen’s room to the bathroom naked?”. Not really anything special normally but now Susan was hear, the chance of accidentally flashing her got my heart pumping. “Fuck it” was my answer to that question. I liked the idea. I strutted across the landing into the bathroom, took a fleeting glance downstairs as my bare arse and swinging dick was free to be viewed but nothing. I was so disappointed. Oh well let’s at least enjoy the bath and use those panties to fantasise.

After having sorted out the bath, I got in and it wasn’t too long until Karen arrived with my beers, she only brought two up she can’t have wanted me to stay in there long. They were cold and delightful.

“I’m going to get some takeaway food for dinner do you have a preference?”

Karen was heading out for food, my playful side sparked into action and made me think of being alone with Susan so I suggested a place on the other side of town. A lovely Italian that made fresh food but also did takeout. She’d be gone at least an hour, I could be very naughty with Susan in that time. I must admit at this point I wasn’t exactly sure what was gonna happen with my MIL, but I was gonna see how the situation developed. Karen agreed and she knew what I wanted. They do a great homemade Lasagne, that with some garlic bread and some profiteroles for after.

I heard the front door shut and Karen drove the car away. It was just me and Susan in the house. Alone. I was down to my last half can, for goodness sake why did Karen only bring up two? Never mind I was gonna get out and get changed to begin working on Susan and see how playful she still was.

Then I heard it, footsteps coming up the stairs. My eyes darted to the door, we don’t have a lock and Karen left the door a little more open than ajar. Just enough to peep through. I liked that actually, maybe Susan would peer in to see what I was upto. That was it, I was rock hard and started rubbing my cock. Sure enough the footsteps ceased and in my head Susan was leering at me as I stroked my cock. Within 30 seconds I had cum. Knowing I was being watched was such a turn on. And by Karen’s mother of all people.

After a couple of minutes I figured Susan had gone back down stairs but without warning she knocked at the door and asked “sorry to bother you James, I know you’re in the bath and all naked but I left something in there whilst i was changing earlier. Would you mind if I retrieve it quickly?” Given the situation I was powerless to refuse.

“No not at all Susan, i don’t have any bubbles in but I’m sure it’s nothing you haven’t seen before in your life. Just try not to look him in the eye”

She chuckled and entered, “yes you are quite right James, but it’s something different when it’s your strapping young son in law”.

“Isn’t it just”, I wondered.

She waltzed in not caring that I was fully exposed, she looked me up and down and said “thanks for the show earlier, I’ll have to remember that when I have some time alone. But a picture would be better to remember your dick by.”

I couldn’t believe it, I was right. She was at the door. I couldn’t stop myself, I began to get hard again. Knowing she had watched me got my heart racing. With each beat her eyes got wider as she focussed intently each time I throbbed. Her mouth began to open slightly and her bottom lip curled into her mouth, she bit down on it with her top teeth. Then it happened. She quickly whipped out her phone and took several compromising photos of me. I was powerless to stop her, but coy enough to let it happen.

I was in now. The line had been crossed and I was gonna go for it.

“Susan, would you mind running and getting me another couple of beers please?” I asked her.

“Certainly James. It’s the least I could do to return the favour of you making your MIL all wet in her panties. But oops, how forgetful of me I’m not wearing them. Did you like these that I left for you?”

I couldn’t lie it made me hard as hell and now that she was here i could think of nothing more than to fuck her. For a 55yr old woman she was beautiful. She was in good shape for her age as well. Her curves and mature body were beginning to drive me crazy. I was starting to think of bending her over and grabbing her hair as I forced my cock into her pussy. “Yes they provided me with an appetite for more. I suppose over the course of the next fortnight or so we could maybe enjoy a few more instances of you indulging in voyeurism towards your SIL Susan.”

“I like the way you think” she leaned in and slapped my cock. “Naughty boy, I’m old enough to be your mother. But that cock certainly would fit nicely inside my pussy. Right now it would slide right in but I have to go and get you your beer don’t I?” With that she grabbed her soaked panties, turned and glided out of the bathroom swaying her hips. As she went down stairs I couldn’t stop thinking of what lay ahead. Two hours ago these thoughts never crossed my mind and now I had the perfect opening to be balls deep inside my MIL. And the kicker is she wants it too.

NSFW: yes