Win a Date With Tad Hamilton Ending?

OK...just recently watched the movie Win a Date With Tad Hamilton for the first time...even though it's old. Well in the movie, when she's getting ready to go on the plane to go see Tad for the first time, pete says to rosalee "guard your carnal treasure" ok...what does that mean? I think it may have something to do with sex...maybe..or I may just be reading into it wrong? Can you help me?
Also what happens in the ending? does she choose pete or tad?

He means not to let Tad take advantage of her sexual organs. In other words, keep your "pride".

You have to see it. Its very romantic and adorable.
She ends up with Pete. She finds out the truth that the 7 different smiles did not come from Tad but from Pete, so she goes to find Pete!