Here's a link to a segment of a video I shot when I came home unexpectedly and found my bisexual black buddy (who since 17 has been my lover too) plowing my wife on our marriage bed.
drive.google.com
My buddy is married to her now, after an amicable divorce so he could be. Since the divorce six years ago he has fathered four beautiful healthy children for her with me sometimes having been very close-up and sometimes hands-on during the babymaking on the marriage bed.
My buddy is still my sole homosexual lover and the three of us sleep together and continue to threesome as freely and often as we did during the early days of our living together full-time after I "came clean" and introduced my wife to my drop-dead handsome outstandingly athletic buddy when he was a 19-year-old college student and she fell hopelessly in love with him.
Given the above account, my coming upon my buddy fucking my wife, as shockingly recorded in the above video, on the face of it was mercifully not as shocking or traumatic as your first witnessing your girlfriend being fucked by her lover apparently was. That said, even these days whenever I chance upon my buddy and my ex privately making love, especially bareback on our bed, the erotic impact and visual spectacle of my buddy's powerfully thrusting body mounted over my ex---not to mention the frantically inter-thrusting genitals as portrayed in the video---can be as if not more shocking in its effect on me as it was on the first occasion I arrived home unexpectedly to find them fucking.
It's a strange thing jealousy, isn't it. It can rear its ugly head at the most unexpected (and expected) times no matter how "proofed" against it we deluded willfully deceived males pride ourselves as being.