She clearly is his beard and they both can see the cameras there.
There are celebs in the closet and they get married to hide their sexuality. These people have reps to protect and they would go to extremes to make it look real, etc.
My bet that Joe is bi, I'd be surprised if he was straight.
+ Wasn't there a picture of him walking down some street with a girl and HE had shaved / waxed his legs?