Not sure if he's over her... Part 2.

So just to recap a little bit...

I recently posted about my boyfriends ex gf. I noticed that he is constantly looking this girl up on his Facebook page. It not weekly, at least monthly. And he doesn't do this with anybody else's page. They've known each other since 2009 and dated while he was deployed in Afghanistan. They were the on again/off again couple from what i remember hearing of her. Theyre still friends, but not very close. They message eachother on bdays and she sends him occassional texts. There has been this ziploc box stashed away in our kitchen drawer for 3 years now with letters from her that she sent him overseas. Sexual and meaningful.. made me want to vomit and I couldn't bare to read but maybe 2 sentences. There's also a series of old kept hotel cards that smell of perfume, and numerous keys (some of which are pink so I know they're not his).

After 3 years I finally brought up the fact I'm insecure about this box. He doesn't know that I saw he looks her up on Facebook often, but that leads me to believe he still has lingering feelings. I did mention that it was weird recently they kept up with eachother on fb.

These are from our convo. And I'm not sure how to respond to this... anybody have advice?