Maybe he can't have it easily removed and has to go through his ex-girlfriend and for whatever reason is very bothered? For fear of rocking the boat? In turn, he may be mentally blowing it off so as to not have to do some damage control with the Ex. (<--Perhaps this may be why he chooses to not do anything about it. If there is something substantial here, you may just have to take comfort in the fact this was before you and that he means nothing against you by leaving it well alone.)

However:

*IF* he is capable of having the video taken down, but chooses to not to, I would be curious as to why. What does he gains by leaving a video up for the world to see of him having sex with another woman? What would he lose by having it removed? (If he is capable of having it *easily* removed, it would be a kind gesture of *respect* for him to follow through with ensuring your comfort. You wouldn't be asking him for much, but a simple phone call, text, or click of a button.)