My Wife's Younger Brother

Just over two hours ago, my twenty four year old brother in law, Alex, got in a taxi to go home.
He'd spent the night in our bed, pretty much receiving my eight inches in his mouth and arsehole, all night long.
We began fucking ten months ago when he discovered my profile on a gay hookup site.
He figured out it was me, even though I don't have any facial pictures on my profile, by viewing the tattoo I have on my lower abs, just above my cock.
Alex had seen the tattoo not long after I had it done and put two and two together.
The same day he saw my profile, he contacted me. We met at a car park where he showed me screen shots of my profile. When I asked him what he intended to do with the pictures, thinking Alex was going to inform his sister, he put his hand on my cock bulge and said "Fuck me".
Alex sucked on my dick after we got into the back seat of my car, then using a condom he gave me, I fucked him doggy, then missionary, before he came all over his stomach and chest.
When I came, I'd pulled out of his arse, moved up, removed the condom and jerked above his face. But I also filmed myself cumming all over his outstretched tongue and neck,
as Alex pleaded with me to "Feed it to me" .
After the sex and getting cleaned up, he asked me if I'd like to make it a regular thing.
The following day we fucked in his car, with Alex dressed up as a girl. It was by far the horniest sex I'd ever had to that point, as we had two guys watching and wanking close by.
We still fuck at the car park, but usually there's no one at the old rough roaded place.
Last night my wife was in Prague on a Hen party, so Alex stayed over.
Believe me, he had trouble walking to the taxi this morning, as I'd just fucked him again over our kitchen table. He got in the taxi sore but happy and with my cum load up his fuck hole.
In about an hour, I'll go and pick up his sister. No doubt she'll have had a good time in Prague, and possibly gotten herself fucked by some lucky guy.
I'm not jealous, in fact it'd be horny if she's been fucked over there.
If I ever found out she'd been screwing around, and believe
me she's pretty and fit enough to do so, then I'd confess about fucking her brother Alex. Until then we're just going to have to carry on fucking in secret.