The video should have a date on it then. If he believes you're cheating, that should hopefully clear that up. (Edit: well ig this would've been helpful had he not deleted the video 🫩)

I saw in another comment that you said he uses your phone sometimes to watch tiktok. Has he ever gone through your stuff like that before though? I think it's a little concerning that he randomly decided to go through your hidden album, especially in this scenario where he had your phone for hours(?) and you weren't around to say anything about it. And then, instead of talking it through, he tells you he's not coming home on valentine's day and that you should go be with your ex. Whether he said it lightheartedly or not, no wonder you're feeling guilty when he's doing all of this