Anniversary
It wasn't terribly dramatic. Holly forgave Artemis eventually, but knew he was still too young. Artemis knew Holly had sensible reasons why not that had nothing to do with the betrayal.
Neither pushed, for or away, they just drifted into it. Kisses on the cheek took longer, migrated inwards and downwards. Hugs, and hands, began to linger, never straying but no longer chaste.
Neither was entirely sure when they moved from unresolved romantic tension to being together.
It made pinpointing their anniversary difficult, to Holly's relief. She couldn't be blamed for forgetting it if she'd never known to begin with.