She walked in on us

So it's finally happened. Truthfully, it's happened many times before but she was younger then and has no questions. My six year old daughter walked in on her father and I while we were having sex. The door was closed but not locked (we only have a lock on the bathroom door) and she walked on to give her father some candy. After shooing her away and after we were done; my conversation with her went like this: Her "you guys aren't naked anymore!" Me "we were having an adult discussion while naked" Her "ewww why were you having a discussion naked?" Me "it's what married people do sometimes!" Her "yuck, I hope I was born after that discussion" Me "well that's how you got here" Her "ewww you mean you were naked when I was born?" Me "actually I had on a hospital gown..." said as I vacated the living room. So Glo friends, how do I discuss what happened with my six year old? I don't want her telling her teachers and friends about her parents naked discussions