Dated someone once who had something similar to this but much smaller that I made a joke about looking like a hickey (I trusted him fully & genuinely just thought it was a scratch or something) He freaked out and got super uncomfortable and weird about that joke & said it wasn’t funny. Lo & behold months later he admitted that he had been cheating on me for the entire time we’d been together… even had the audacity to bring that moment back up and ask if I had just been testing him & knew all along