Bubblenesting is an instinctual thing. Bettas do it when they get that special bubblenesty feeling--as bettas age they tend to do it less and less. But if your boy is young and happy, you can encourage him to make a new nest by putting something on the surface for him to build his nest under, such as the cut-out center of a paper plate or styrofoam cup. Many people, including myself, condition their water with dried indian almond leaves--this makes the water resemble the water found in the betta's natural habitat and stimulates their breeding instinct, prompting them to build more nests.
Could you tell us a bit more about your betta and his home? What size tank is it, is it heated? What's your water change schedule like?
I saw that you posted on my profile page, and while that is an acceptable place to post, I think it would benefit you more to continue the conversation here because you would get a lot more useful feedback from people who actually breed bettas. If you would rather talk about this in PM, just let me know. :)
Could you tell us as much as you can, please, about your breeding set up, the pair you've chosen, and what you plan to feed the fry?
To be honest, I think you need to do a lot more research before you start trying to breed bettas. It is very expensive and can be very tricky due to the behavioral peculiarities of the species. Breeding bettas is not something that is practical for the average hobbyist, and due to the huge amount of unwanted pets in the world, we strongly discourage people who are new to the hobby to start breeding bettas when they have no knowledge of betta genetics, how to orchestrate a successful spawn, and how to take care of the fry.
Please do more research and keep your bettas separate until you really know what you're doing. One day after you have absorbed all the necessary knowledge and can set out with a goal of what specifically you plan to achieve through breeding (be it, to create a winning show betta or to establish a line of your own or to maintain a line of bettas) you can purchase a quality pair from a breeder and try your hand at it.
Throwing two random bettas you bought from a pet store together is only going to get your male and female injured.