Consider yourself lucky. About seven years ago I got caught by my dad doing my girl doggie style in my room.
Thankfully, there were really no consequences to it. He walked in, blinked, turned around and walked out. Later, the conversation went like this:
Dad: You better have been using a condom.
Me: Yeah, I was.
Dad: You should wait until you know no one is home to do that.
Me: Anything else?
Dad: I thought you had better taste in women.
Me: ??!1 wtf
Dad: Is your girlfriend embarassed?
Me: Oh, she's not my girlfriend.
Dad: She isn't?
Me: By the way, my girlfriend is coming over for dinner tomorrow night.
Dad: I thought you said she wasn't your girlfriend.
Me: She isn't. My actual girlfriend is coming over tomorrow night, and I'd like for this not to be mentioned.
Dad: Oh. Okay.
Of course he brings it up, and of course I get dumped. Parents can be evil.
Not that I cheated on her. In no way had I ever said, "commitment." I still stand by this logic.