I don’t know why I’m upset about this

So my boyfriend and I are currently long distance, so there’s a fair amount of nudes and sexy videos and stuff like that. A few days ago I sent him a few nudes and a video over snapchat. He texted me to ask if I cared if his friend saw them since he wasn’t going to get a minute alone. I said no to the photos, yes to the videos. As in, no I don’t care if they saw the photos, but yes I care if they saw the videos. He did it backwards and kept the nudes private, but he showed his best friend a video of me masturbating. I’m not angry with him because he just misunderstood and I should’ve been clearer, but I’m still really kind of upset about it.

When I talked to him about it he seemed like he felt bad about it and he apologized, but I can’t shake this. Advice?

Edit: Some of you guys are saying I shouldn’t be okay with his friend seeing photos. I am, and he wouldn’t show anyone anything if I wasn’t. I’m more looking to try and shake the embarrassment of someone having seen a video of me getting off.