I have noticed them side by side staring at parts of the tank - the castles, the plant leaves, and even the glass. This is common when they are considering laying eggs. I would love to know how they communicate; I can imagine them asking each other if they think the conditions are right in that particular spot for the eggs to flourish.
Here is Lindsay; he is about ten inches tall and about two years old now. He's fathered several hundred eggs!
This is a small tank; only 20 gallons. Though books recommend five gallons for each angelfish, I allow ten gallons for each one. Only Lindsay and Stevie live in this one, so there are no predators and their eggs and fry would be safe.