Yes, it’s even sadder that she probably felt comfortable with him. Combine the way she was dressed, no or little make-up, and the fact that she had just returned from her grandmother’s funeral, and I believe she was comfortable with him. I clearly remember the summer my grandfather died when I was in college and I’m putting myself in her shoes.
I also have a gut instinct about the friend who warned her. I have nothing to base this on except my gut and experience, but I’m betting he was at least a little bit in love with Kelsie. And if she sensed that, she may have taken his warnings less seriously, thinking perhaps it was just jealousy.