WHAT THE??????!!!!!!!!????????

So I came downstairs this afternoon after spending a few moments in the bathroom to find that I was missing two kids. The younger three were all sitting watching a movie n=but the older two were gone. Daniel appears from the dark laundry room and a second later the girl I watch after school also appears. When they were asked what they were doing Daniel pipes up with..." we were talking" I asked about what and he couldn't come up with an answer. I then sent him upstairs so I could interrogate them seperatly. I asked said girl and she claimed forgetfulness. I kept at her until finally I told her to get it figured out in her mind by the time I came back. Daniel eventually told me that they were talking about the movie cos they didn't like it. I came back down and finally got out of the girlie that Daniel had asked her to find his ticklish spot. I was horrified! So back upstairs I went armed with the conflicting story, telling him that there would be serious consequences for lying. He finally spilled out a similar yet not totally the same story.
I can't believe this. They are almost 9 and 6. What is going on and how much further would the tickle game have gone if I hadn't come down?!? She is always writing letters to him, making him cards expressing her love to him. I realize they are just kids but it seems so early for them to even notice each other never mind going to a dark room together!
HELP!!!!!!!