My friends dad kept taking videos of my mouth.... why??

I know this will sound so weird, but I remember this as clear as day, I was over at a friends house, this was maybe 9 years ago, or 7, I don't remember. But I was there for 2 days, and the dad would randomly start recording me as we sat on the couch watching a movie (not anything sexual), but he would specifically record my mouth.<br><br>I don't know why, and I never asked because I felt so weird asking. I just don't get it, and it has been stuck in my mind for so long since this happened.