It's Not My Fault

Is it my fault I have an eight and three quarter inch thick cock.
Is it my fault my wife who I married fourteen years ago, no longer enjoys or wants sex.
And is it my fault my twenty year old step daughter Emily adores having me fuck her mouth, pussy and arse.
Emily practically blackmailed me into having sex two years ago, when she walked in on me fucking a teenage friend of hers.
She was supposed to be at her boyfriend's, but they'd argued. My wife was on a late shift, so I invited my step daughters friend around, knowing she wanted my cock.
It's a long story about how I knew she wanted my dick, so I'll not bore you with it. What I will say, is at first I tried not to indulge sexually with a very pretty, if not a slut, girl. However when she told me she loved anal, I just had to see if she could take all of my cock up her shit box.
I was actually balls deep up her pussy from behind when Emily walked in. I thought she was going to go mental and threaten to tell her mum. Instead my step daughter had her friend move aside a she sucked in my cock.
It wasn't exactly a threesome, as they didn't interact at all, but I did fuck both girls until I finally shot my wad up Emily's friends beautiful arse.
And that's how my step daughter began getting what she wanted. And that meant my cock on tap too.
Every time she was horny, she'd message me, saying "White flag". It was her little joke about me having to surrender to her sexual will, knowing she could spill the beans at any time.
At first the sex was fairly vanilla, but once Emily experienced my cock fully inserted up her bum, she became ultra sexual. Often having me fuck solely her arsehole.
There has been many occasions over the two years, where we've fucked with her mum only feet away. Usually asleep after a long shift, or when she'd been drinking wine.
On one occasion I can think of, I was fucking Emily on my chair in the lounge. My wife was asleep on the sofa, but woke up as Emily orgasmed.
She'd had two bottles of wine, so my wife's recognition of what was happening was fuzzy.
She thought we were practicing jiu jitsu, something I love. What maybe shouldn't have added up, was we were both practically naked and her daughters arsehole was impaled on my cock.
Within seconds she fell back to sleep and I put Emily on her back, then entered her pussy missionary.
Another time, as my wife chatted to our neighbour over the fence, I fucked Emily from behind, as she breathlessly joined in the conversations leaning out of the kitchen window.
Two years on from our first fuck, my step daughter has recently asked me if we should begin sleeping together. When I mentioned her mum, Emily responded "She's known for over a year".
I genuinely didn't know my wife knew I was fucking her daughter. She's never said anything, not once.
It helps that my wife and I don't sleep in the same room anymore, but it might seem strange sleeping with Emily, knowing her mum, my wife is right next door in the next bedroom.