To be honest, the heavy and deep emotional feelings I have when looking at the pictures stop any form of arousal from emerging; The pictures haven't once made me wish to be back with another ex either.
And as for me, I won't look back when I'm feeling aroused or anything.
.
I'd absolutely delete them if they asked me to, but I think your expectation that they should be automatically deleted once the relationship ends is a bit.
This seems fine, cute even.
And I mean trust in the kind of person they are, not in how much they love you or turn you on and make you want to send them nudes.