He will build another one, might sulk but no more than he will when you take him away from his precious babies :roll:
Water quality is the most important thing in getting them to breed. Leave the filter turned off rather than turn it on and off which is what will cause water quality problems. You might be able to - with a bit of fiddling run a sponge filter into the tank with an airline. Siamese fighters are air breathers but bn are not unless absolutely desperate. BN are also very messy so you should set yourself up a good water change/tank vacuum routine.
Good luck.