In my 42g FOWLR
build tank I have a juvenile yellowish clownfish, and he has been in there for a week or two now by himself. Yesterday I went and bought it a mate - another juvenile reddish clownfish (ever so slightly smaller).
All was going well when I introduced the new fish into the tank, they were doing this weird twitch dance next to each other - see pics:
After they finish the dance, the red one chases the yellow around quite a bit. They stop this, and resume their dance. The chase does look quite aggressive, but if the yellow didn't like it, there are hundreds of places for him to hide in the rock.
I fed them some live brine and the red one ate a few, but spat them back out.
Today, the red clown has eaten and they look happy - they stay close to each other and it doesn't look like the red is chasing the yellow anymore.
Will see how it goes - hopefully these two pair off!
Will keep you updated