They are still mating, and his tummy looks really fat.

I have a pair spawning this very moment. They've been in the spawn tank since Friday and they just figured it out today. Sometimes it takes a while with first timers. If there is no bubblenest, put something in the tank so that the male can build one. I use an almond leaf as it conditions the water. Half of a styrofoam cup works well too. If there are more Betta's in the tank, the natural territorial urges may be taking over before the male has time to build a nest. I've noticed my not terribly bright boy has been building the nest as he spawns. He had a skimpy nest going under the leaf before he finally realized he needed to squeeze her belly, not her head, but he's been adding to it as he collects the eggs. She's been collecting them as well, spitting them into the nest. Then he comes along and adds bubbles to the clump.

If they are still at it, put half a styrofoam cup or some other floating item in the tank so that he has a place to deposit the eggs. Otherwise it is unlikely you will have any babies. If you do manage to hatch some fry, you will need to remove the adults or they will eat them. Trying to remove the babies will be difficult...