Don't worry. U can't disturb them when they r mating. Feed them 2-3 times. Atleast 2 time. Once he is parallel to the female, the male strongly vibrates. If the female is ready to spawn, she vibrates and stays next to the male. They may entwine tails, and the male occasionally rubs his brood pouch against her ventral area.
The male keeps vibrating, is that normal?
It's normal. U might see that female will start vibrate now when she is ready to mate. After that, The male’s pouch swells, and the orifice at the top of the pouch opens. His movements appear aimed at drawing the female’s attention to the pouch. She inserts her ovipositor into the pouch and transfers the eggs, which takes about five seconds. As soon as the eggs are transferred, they are fertilized and the brood pouch seals shut. U can refer this article. Here is what happen during spawning and after
