Still Don't Understand

Went to the gym with a good life long friend. We were in separate showers. Bullshitting with some of the guys. I caught Trent stroaking soap down his dick. He was just cleaning himself. But I was kind of taken back.
We went to elementary middle and high school together. Then we both went to college. Trent is tall skinny athletic shirt naturally spiked black hair. Six foot even chill mellow guy.
I'm five foot ten a slight gut still in shape dad bod. Short trimmed bearded face. Stocky broad build.
We get in my house after listing to him bitch about how his wife Jenny has been holding out on him not putting out.
I'm interested in seeing his issue solved.
My wife Sarah is five foot six short curly red hair petite curvy body small shapely butt and amazing legs. Ample breast small d cup large c cup. Sexy round little face almond eyes .
Me and Trent grab a drink out of the fridge Sarah my wife is watering the house plants. Wearing a pair of thigh hip hugging shorts hugging her small round ass the shorts stopping inches under her butt. And a purple halter top that tied behind her neck and stopped at the top of her belly button.
I whispered in her ear Trent has a problem meet me up stairs in the man cave.
Like a person possessed I was going to ambush them both.
It's nothing for the three of us to smoke a joint in the man cave away from the kids.
We get in Sarah joining us a minute later.
I've sound proofed the walls with half inch Styrofoam floor Rubber mats my ps4 banter can be a bit much.. Air brushing pop art and tattoo art on them.
Sara walking in I stand up and meet her.
I've got a recliner and a blue futon couch in the room a end table pot stash and a coffee table a 50 inch TV and a mini fridge in the room.
I stop Sarah and tell her trents problem has to be solved.
She says agreed
Then we smoke a joint
Agreed she says again
I grab the waist of her shorts and slid them down.
What the fuck kind of issue dose Trent have she asked
Blue balls I tell her.
Owe in that case she says as her shorts hit the ground.
Her pink Victoria secret cheek panties showing off her already wet pussy. I untied the bow holding up her halter top.
Her top falls off exposing her pink gum drop nipples.
Skip through the tee hee witty puns and Sarah's shy moment.
Trent takes off his tee shirt shorts and gets undressed.
Small pect's rippled six pack. Sarah kissing down his torso.
Trent takes off Sarah's panties and then his briefs.
Sarah looks at his dick and raised her eye brows wow she says. Literally a fat oval of meat with a large bell shaped head a thick soft six or seven inch dick hanging over a tennis ball sized nut sack.
My obsession with seeing his dick inside of Sarah inching closer.
Her short trimmed red pubic gleamed in the light.
Five foot six short red hair in his hand small next to him.
She did not hesitate she sucked his dick and started deep throating him.
He came quickly in her throat.
Her large upturned tits in his hand his fingers over her pink rings gum drop nipples rolling in her fingers as he sat her down eating her pussy like a pro.
Her small feet curving her breathing getting heavy and heavily humming whimpered moans out Trent sucking on Sarah pussy.
Her sexy legs spread open toes on the coffee table. Trents now nine or ten inch fat vein covered dick bouncing with excitement.
Sarah's tight wet pink pussys slit dripping with a small opening oozing out her clear wet juice.
He rises up over her he sits down and pulls her over him her tits on his chest. Throwing her leg over him grabbing his dick paused strattaling over him.
His fat big bell shaped head splitting her pussy lips open stretching her wide open. She lowered herself down his dick .
She rode I'm slowly lifting and bobbing back down to the base of his shaft.
After afew minutes she is throwing herself up him and slamming down with a soft landing with a wild grind.
Her tits in her moth holing her neck sucking on her tits.
She rode him roughly almost breaking my futon.
He stud up her legs wrapping around him he fucked her standing up dropping her on his dick. I stood up and he dropped legs open in my chair. Fucking her in a standing pose missionary in my recliner fucking her hard and deep. Sarah moaning out her tits bouncing toes curled she wrapped her arms and legs up around him.
He bent her over the back of the futon pounding her doggy style.
He lasted awhile fucking her from behind. Sarah's ass bouncing rapidly with him pounding her.
He came loudly busting inside of her. Sarah sat naked next to him her pussy leaking out cum as we smoked a joint then two joints. He fucked her one more time in missionary fucking her tiny petite shapely body into submission.
Her sexy legs on his shoulders.
Power fucking her for nearly forty minutes. Holding her legs open or grabbing her thighs pulling her onto him grabbing her feet and holding on to them as he pressed into her.
We smoked again he took another shower and Trent went home to Jenny.
Me and Sarah smoked and talked.
I did not understand my obsession with seeing trents dick nor mean to get obsessed with him fucking Sarah.
It was our first experience sexually in eight years with anyone other then just us. We both enjoyed it and it broke up the rutt in our sex life
We had full disclosure of our fantasies fetishes and what we want to try.
I am understanding why they call um the dirty thirties