<human>: Can you summarize the given text in a few sentences?

The other day my younger brother (we'll call him Ryan) told me that he came home from his friend's house and walked upstairs, and saw porn playing on the computer in our father's office and him sitting in a chair. He said he couldn't see exactly what he was doing, but he could guess. Ryan seemed very upset by what he saw. He was concerned about our parent's marriage (they've been happily married for 25 years) and seemed troubled overall. Ryan says our father doesn't know he saw him. He ran back outside after he saw what was going on. 

Our father and family as a whole is pretty reserved. We don't talk openly about these types of things, and I know my dad would be very embarrassed if he found out my brother saw him. 

I reassured Ryan that their marriage is fine, and that masturbating isn't evil or unhealthy. I ended the conservation quickly though because I felt really uncomfortable and was totally caught off guard. I always assumed my father masturbated, but I've never seen him do it. He's never talked to us about masturbation so it would be pretty uncomfortable bringing it up. 

Should I tell my father about this? Should I talk to Ryan again? This happened a few days ago and he's still quiet around our dad. Thank guys!
<bot>: My younger brother saw our dad watching porn and masturbating. He came to me distressed, and I'm not sure what else I should do.