He was most defintely missing his mate!
After two days of Bruce pacing back and forth outside of the chicken coop, I finally put him and Luca in with the hens.
Even though, Luca didn't seem to mind just "baching it" with his Dad!
There is a ladder (that I MADE!) that goes up to the open window so that they can go outside but, thus far, nobody has seen fit to venture out. Of course, I do shut the window at night...