My wife Enid was out having a few drinks with her older sister Maxi. Both women are dark haired, dark eyes, petite with round arses. Beautiful women in their 50s.

Unusually Maxi was having a few drinks too many! She was getting plastered! Enid as usual kept her cool - Maybe tipsy, but no more.

"so" Maxi declares "John won't fuck me anymore"

She starts to regale Enid with tales of her husband and his diminished libido.

"We don't have that issue " Enid says

"Hmm! You won't give him your arse!" Maxi shouts

Enid is mortified! Wishing she had never imparted this information to her sister.

"If Charlie was mine I'd give him all the anal he wanted!" She slurs "you know Enid, I actually prefer it! I dildo my arse while my useless husband stays up watching Newsnight!"

Enid is shushing her

"I dildo my arse and pretend I'm YOU Enid! I pretend Charlie is up my bottom!" She screeches drunkenly

"Yknow Enid, you should invite me round to give my rear to your husband. Enid you'd be doing both of us a favour! All three of us! Charlie gets to fuck a bum - his favourite fantasy! I get my bum fucked! YOU get the evening off!" With this she roars with laughter.

Enid is appalled at this uncharacteristic outburst, excusing her sister, her insobriety, her marital woes.

But also she is aroused.

Later, much later Enid imparts this bizarre conversation to me. I have to fake being shocked. When really my cock stiffens, my face reddens...

We don't mention it, Enid and Maxi continue to enjoy a cloudy sisterly relationship, I play badminton regularly with John.

But the information is lodged. I can't look at John without imagining him just sitting there, watching TV, while his wife touches her own bottom. I look longer, more longingly at Maxi, her curvaceous arse, crammed into leggings. I often drift, imagine Maxi imagining ME. A penis substitute stuffed into her forbidden exit, while she thinks it's me! Me! I watch Enid walking her wiggly walk and think about penetrating her anus! As we fuck - happily, regularly - i pretend she's her sister, I pretend I am not in her pussy.

Months go by and the incident is never mentioned Then, one evening Enid instigates sex in one of my favourite ways, taking off her knickers, warm and well marinated hands them to me to sniff. As she does she says:

" Do you think Maxi smells similar?"

I am so hard - Enid can teach - we fuck and she is gushing. She whispers:

" Pretend I'm Maxi"

I cum, buckets!.

In the afterglow of orgasm she says that, That Night, the evening Maxi revealed all, her and John DID fuck. The revelation unblocked them.

But John is into the fantasy. He likes the idea of me, Charlie, his brother in law, fuckin his wife. In the arse.

I ask Enid what SHE thinks about that....

" I want to watch" she says...

To be continued...