The post-anther lobe looks a bit more notched here, and it has more numerous flowers. I wonder about something like arenaria or brevifolia - do you have photos of the leaf?
Alright. I've put as pauciflora complex as it doesn't look quite like typical pauciflora, and particularly if the pink one was smaller this one could be something different
Went to check the leaf and indeed eaten to well within an inch of its life. However, quite broad at the base, about 12mm, and not fleshy. Flowers not open.