A considerate dude who frequently/diligently tidies/smoothes/re-adjusts the blankets/pillows while canoodling in bed with you, just as the well-known feathered grass-walled-nest dweller does to please a female who drops in to visit.
Tiffany always appreciates my being a bower-bird bed-buddy, since it feels so much more pleasant to sleep with me if the blankets are always neat and uniformly covering us, especially during the cooler seasons.
Nathan-
A term used to describe an especially perky boner in public that is unable to be hidden.
"Sam, I was in the office reviewing papers when I noticed a female who had an incredibly attractive body. I instantly had a Nathan, and when she turned around, her face was just as magnificent as her body, at which point my Nathan turned into a BIG BIRD BONER."