TMZ reports that boxing champion Floyd Mayweather witnessed a murder-suicide on FaceTime. The site says Mayweather was on the videotelephone app with one of his best friends when the man pulled out a gun, shot his wife, and then killed himself. The site cites sources saying rapper Earl Hayes called Mayweather on FaceTime on Monday because he was upset over claims that his wife, VH1 star Stephanie Moseley, had been unfaithful. The sources said the boxing champ was pleading with Hayes to get a grip, but to no avail. Mayweather was not saying how much he saw, but he acknowledged he was a witness and heard everything, TMZ reports. NBC4 Los Angeles reported that authorities confirmed Hayes and Moseley were killed in an apparent murder-suicide.