‘It's not humiliating. It's not about her partner at all, it's nothing to do with him so he can't be humiliated.
She's said she forgot they were there. She could have said "oh sorry forgot about those, I'll delete them now" and that could have been the end of it.
Any acts she will or won't do with him, for whatever reasons, are a completely separate issue. If he felt bad about what he saw (when snooping), then it was for him to deal with. It's his choice to draw the line where he wants, but he shouldn't be shaming the OP.’
What has become of empathy and nuanced thought?!
He feels it is to do with him, as clearly he feels she was attracted to her ex enough to do ‘the act’ but not to him. Hence the ‘humiliation’. That may be completely untrue but that doesn’t invalidate his feelings.
I am not totally believing of the OP when she says she didn’t feel comfortable etc. Of course, that is possible with simultaneously finding reviewing them exciting. As PP have said, there are six videos (the OP hasn’t said they were snippets or taken at the same time), so it is reasonable to assume that they were taken separately and kept.
It is one of those difficult situations on both sides. He feels bad but, using (a particular type) of pure logic, he shouldn’t care. After all, it all happened long ago (not necessarily as long as people are assuming, she says her photos go back 10 years, not that these videos are 10 years old, they could be much newer) and everyone is allowed a previous sex life.
And no one owns anyone else’s body, he needs to respect her boundaries.
But….
The majority of people expect sex in a relationship and, for different people, that may include different acts (oral, for instance). Is expecting a guy to do oral ‘owning them’ or ‘controlling’ them, or a reasonable condition within the context of a relationship?
There are no black and white answers and I don’t think it it unreasonable he is upset and may need some time alone to process. Ultimately, if OP wants to continue the relationship, they need to have an honest conversation. If she doesn’t, of course, that is equally her prerogative.