A rapper killed his actress wife and then shot himself in a gruesome murder-suicide today—all, apparently, while Floyd Mayweather watched in horror over FaceTime.

The story, via TMZ:

Sources tell us ... rapper Earl Hayes called Floyd on FaceTime Monday morning in a rage, over claims his wife — VH1 star Stephanie Moseley — had been unfaithful.

According to our Floyd sources, Earl said he was going to kill his wife. The champ was pleading with him to get a grip ... to no avail. Floyd will not say how much he saw, but he acknowledges he was a witness and heard everything

TMZ also reports Hayes, who was close friends with Mayweather, accused Moseley of cheating on him with a "famous singer." Neighbors at the couple's upscale Los Angeles apartment complex reportedly heard multiple gunshots ring out around 7:30 a.m. and called police, who discovered their bodies.