Cresties Mating or Fighting?!?! HELP!

Hi guys!
So I have a situation. I purchased a crested gecko which I named Miku about a year and nine months ago and believed it was a female this entire time. I decided to get it a little buddy about a month ago. I then purchased a female who is a year and a couple months old and named her Mizuki. I went through all the percautions and then introduced her. For a long while they knew about each other but just stayed away, didn't fight or stare at each other if anything they seemed content and both were eating. After a while I noticed my Miku had a bulge under its tail and realized, oh no. It's a boy...welcome mating! Two days ago I noticed something. Miku decided in the middle of the day to have a stare down with my Mizuki. They were face-to-face and then BAM! Miku bit Mizuki in the nose. Mizuki didn't attack back and that was the end of it. Then I noticed they started to follow each other a lot more with biting involved...not on the tail or anything, just weird fits of biting on the face or back of the head. I heard this was their way of "mating" and that it's basically a fight for dominance. But during the day I notice they are pretty content, Mizuki goes to her usual spot under the leaves to sleep & Miku tends to stay awake during the day a lot (he even did this before Mizuki came along) either on a branch above her or on a wall to sleep later on but no attacking or harassing each other. Now my female Mizuki is a bit larger than my male Miku. She didn't start attacking back until last night in which I noticed Miku wasn't coming after her as often. Could it be because she is bigger than him? My main concerns are:
#1 are they fighting or attempting to mate?
#2 will this hurt one of them because I DO NOT want that.
#3 Mizuki (female) is chasing or "following" Miku and waiting right behind him and then CHOMP biting him or jumping on him is that because they want to mate or something else??
PLEASE HELP I DO NOT WANT THEM TO HATE EACH OTHER! As we speak they are actually going after each other.  

Here is a video of Mizuki attacking Miku on the face taken today. (pardon my language it scared the crap out of me when she attacked him lol)


Please help me out here! I am TOTALLY okay with mating & prepared to take care of any babies as well, I just wanna make sure they're gonna be okay! 
Ashley