spiny devilfish

I believe these odd-shaped bottom dwellers are two variations of the Spiny Devilfish. I have not been able to identified the behavior demonstrated in this video. Is this a failed attempt at mating? or this behavior something else? Can someone help me with this fish ID? I observed this while...

I am quite excited about this video I shot of a Spiny Devilfish, filmed in Dauin, Philippines, with my Olympus E-M1. Parts of it I shot with the Inon "bug-eye" close-focus, wide-angle lens, which I like more and more for video (it needs a bit too much light for photography imo). This is an...