Rare sight of hummingbirds sharing feeder

The Anna's hummingbirds that visit the garden are very territorial and never share the nectar feeder with others. We are accustomed to observing these birds chasing each other away from this nectar source, like little fierce jet fighters.

Imagine our surprise to see these two hummingbirds actually sharing the feeder. The one on the left allowed the one landing on the right side of the feeder to drink from one of the other holes. Maybe they are a pair, or parent and child or siblings?