If we're talking about NTR, then the discussion isn't complete till Kitasan Black is involved.

>Kitasan Black could never defeat Duramente.
>Duramente retired however, seemingly freeing Kitasan from Duramente.
>At the time, Kitasan was noted to have a thing for Sweep Tosho. A beautiful mare of his generation.
>He paid attention to her in stables and on the track, his desire for her clear to both his team and to his fans.
>His team planned to mate Kitasan with her, but during that time? Kitasan was much too busy to do it immediately.
>Unfortunately...
>Duramente's team found out.
>Swooped in and Sweeped Tosho First.
>While Kitasan ran, his rival indulged.
>Kitasan would only get Duramente's sloppy seconds.
>And yet this story of rivalry and anguish for our Season 3 hero didn't end there.
>Kitasan would soon after get a new little brother from his mother, Sugar Plum... Courtesy of Duramente...

Duramente-sama... S-stop it...

Duramente... Please... Leave my wife alone...

>Be IRL Kitasan Black
>Incredibly prodigious, life is set for you to be a winner, all is good
>One problem
>Duramente
>Can't beat that fucker
>He also goes and retires meaning you never get that W back
>But it's okay
>Life isn't all about beating Duramente
>Life is about love
>Sweep Tosho, now that's a sexy mare
>Want her deeply, your team are gonna get you with her
>Lil busy right now so it'll have to wait
>... Duramente's team aren't busy
>Those fuckers snipe in and mate Sweep Tosho first
>Beautiful Sweep wife has been bred and impregnated by that BASTARD Duramente
>But it's okay
>Still get Sweep Tosho eventually, so it's not so bad, right?
>Duramente can't hurt you anymor-
>Duramente just fucked your mother Sugar Plum
>You now have a little brother sired by the horse you hate most
>FUCK.