You sound fairly open-minded and horny, so here's a fantasy :
'You're wearing just your boxer shorts. Your wife has very thoughtfully prepared you for this particular pleasure. I'm standing behind you, a hand discreetly moves and fondles your balls through the material of your shorts. Your cock stirs and is soon stiff....I have to ease the elastic over your cock, the shorts drop to the floor and you step out of them. Wearing a well lubricated condom as requested, my erect cock rubs up and down the cleft of your bottom - this excites you and you obediently lean forward slightly.
My right hand reaches around your body and is gently rubbing your cock - my left is guiding my shaft into your anus. Your wife's efforts with the dildo have helped you - there is no pain as you are entered, only pleasure ! You've been waiting a long time for this. My cock is eased up so that my balls are pressing on your bum cleft - a gentle rhythm is set up, so that your cock is being milked as well.
The pleasure is too much, and soon your come is squirting out of your cock. Slowly, I pull out my cock - the condom is full of seed. Satisfied at last, you bid me farewell.
Anon
PS Your comments are welcome on my literary efforts !