Male Betta not blowing a bubble nest

Question
QUESTION: Hi, i am breeing my two bettas. The male always flares his gills at the female (divided tank) and she flares hers back. They seem to like eachother. I have my styrofoam cup in the tank for the male but he still isnt making a bubble nest. He never has even before I got the female. The tank is the right size, hes energetic, and the temp. is fine! Whats wrong? he is also the correct age!!! Can you please help!?!?
ANSWER: Hi,
Firstly, I would like to point out that Betta fry are incredibly difficult to raise, and are best in a warm pond if you want them to survive. I actually don't know anyone who has raised Betta fry.
Some Bettas just don't want to breed, even in perfect conditions. make sure the tank is filtered properly, but the water is calm and there are no large ripples in the surface. Keep the tank quite warm, around 29 Degrees Celsius is best for them.
Change 20 percent of the water in the tank each day to stimulate him to make a bubble nest.
Do be aware though, they may not spawn. It is not unusual for them not to. It is merely luck a lot of the time.

I hope they do spawn for you.
Best of luck,
Kathryn

---------- FOLLOW-UP ----------

QUESTION: So even though he flares his gills at her he still mite not want to breed? the female is getting fat..... he is VERY interested in her and i mean VERRRRY! is there a way to promote them to make a nest? and do they have to like get used to the female before they make one?  

Answer
Hi,
They will nearly always flare their gills at one another, that is not an actual sign of them wanting to breed.
Just do what I said and slowly lower the water to 26 Degrees Celsius, then raise it again to 30 Degrees Celsius. This should give them the best chance of breeding.
You just have to wait, but if he does not blow one in the next few days you can be sure he will not. Some males, even if they are interested, don't build a bubble nest.
Most people buy 6 or 7 males and choose the one with the biggest bubble nest instead of just wishing with one.
Best of luck,
Kathryn