Sunburns and swimming lessons

So can anybody tell me why, when I put sunscreen on, I get sunburned? And not just a little bit, but bright pink don't-touch-my-legs-or-I'll-scream burned. Hmmph. Good thing Jared tans well, and that he passed that skin down to our kids. Got pics of M and H at swim lessons this week. Since H's hair is wet, you can't see that he's bleached blond from all the sun he's had this week :) And Morgen's at the diving pool- it really is that blue :)