Most likely he'll pair with one. When this happens he may be interested in the other females, however the female that he has paired with will attack any females that approach her territory and will try to prevent him from spawning with other females. The male won't be too interested as long as she continues to spawn. If he senses that she isn't a good mate either because of illness, unsuccessful spawns, or another female becoming the dominant female in the tank he will leave her and pair with the dominant female.