Boyfriend has saves of tiktoks of children online

My boyfriend has both a phone and a tablet and he told me it was a work table. The tablet has a really loud alarm to wake him up in the morning but today he was out of the house when the tablet went off so I went to turn it off and I notice it's on a video. It's a saved tiktok of a little girl using the potty. I go through it and he has over 100 saved tiktoks and little boys and girls either taking a bath or using the potty or in their underwear. Not a single child in these are fully clothed. My heart has been racing. We've been together 2 years. He's been amazing with my 6 year old son. When my son's dad died he has become a father figure to him. I feel sick to my stomach. Could there possibly be any other logical explanation before I confront him?