<human>: Can you condense the text into three sentences or less?

So I my laptop hasn't been working great lately, and I wanted to download some movies to watch, so I got on my dads computer in his office. I never asked for permission because I didn't think it was a big deal. I find the movies and start downloading them and I see that he's downloaded gay porn (I checked, it's legit gay porn)  I didn't know what to do and just deletet my torrents and all traces I was ever on his computer. 

This happened 2 weeks ago and I've been trying not to think about it at all, but last night I was up really late reading and I can hear someone talking outside my window that faces our backyard. At first I thought it was burglers or something and I freaked out, but when I looked out my window I could see my dad standing in our backyard and talking on the phone. This has happened before and I just assumed it was a buisness call or something (he works with people in different time zones), but I got this bad feeling because of the stuff I found on his computer so I eavesdropped. I wish I hadn't because it was obvious he was talking to someone he's having an affair with. When he hung up he said "I love you too, Michael". 

I don't know what to do! I think my dad is having an affair with a man. I thought he and my mom had a happy marriage. Do I tell him I know? Do I tell her? What do I do?
<bot>: Found gay porn on my dads computer and overheard him telling someone on the phone "I love you too, Micheal". I have no idea what to do.