Yes, continuously as well as flicking fins (rubbing). There is so much video. Had to capture their moment. But these are the best I can do on such quick capture of the moment. At least you get the "general" idea.
The upper fish (male I assume) comes under the belly and uses its dorsal fin to "flick" the anal opening (side to side motion). At times it will use the pectoral fins and "tap" the sides of the female (belly region). I'll see if I can capture it on a still. The video is old and I don't want to mess with it to much on stop action. I may have photos already since I took about 40 of them and only posted these few. So what I'll do later today is go through them and if its there I'll post it.
I'm guessing yes. You have to realize this is some rather rare footage, no one has reared acestro eggs in captivity (to my knowledge) and only a few have had this kind of behavior occur. Props to Frank, once again!