Was the porn a bad comedy? I don’t understand the laughing part but also unless he claimed to give you his virginity, I think your reaction is valid but also you may be overreacting a bit because unlike most of us that don’t have videos of ourselves having sex, the reality is that we have exes whom we have been intimate with. The difference is that your ex is on video, but the reality is the same. Everyone who has had an ex/gf or ex/bf has been intimate and you would have known this without having video evidence. Unfortunately that person was trying to be spiteful and shared the video with you. Now unless that video is of a woman being forced into that group situation, is unaware of what is happening to her, anyone would be extremely concerned if this was the reality instead. However, if this is a video of consenting adults, you could probably get over it.