You are way to concerned on the aggression. What he is doing is getting her attention and trying to show her his spawning site. These are fish he can't take her by the hand she will eventually go look and let him know if it is good enough. If it is good enough they will spawn in there. If not he will work at it again and she will check it out. You may also observe them lip locking that is normal. Give them a couple of days together and see what happens. They will probably spawn with in a week or so.