FrostIron, invasion monument
I can’t find FrostIron fic — I remember it had a scene where Tony and Loki walk through a park and end up in front of a monument commemorating those lost in the 2012 invasion. Someone ends up taking pictures of them and Loki obviously feels guilty seeing it. It was Loki redemption thing, it's just... a very specific and poignant scene and if you read it you probably know it, I just can't remember the title.
EDIT: I found it! I actually had the fic downloaded but didn't expect it to be this particular one... It's Love, Acceptance and Whole Lotta Kink https://archiveofourown.org/works/17580419 and it's essentially soft, fluffy, adorable bdsm canon au.