While this is not ideal, it is what it is....Since they seem to be doing fine together-I don't recall for how long, but it seemed like it was a month or longer from what I remember reading on your other thread...Anyway, while its not recommend to keep males and females together-it can be done-it depends on the fish themselves-As long as you understand what you are getting yourself into and the risk involved. Often they will be fine together for a period of time and then
"BAM" one kills or injures the other out of the blue.....Then you have reproduction issue that will almost always happen when you keep opposite sex fish together....lol...
Depending on the setup itself-the offspring may or may not survive and since you don't want to or can't move the female. You can let them do what they do...Reproduce....some fry might survive-you never know-you might even end up with a colony.....Mom, dad and offspring living happy or not so happy together.....
I don't discuss my keeping of Bettas in this manner a lot-but only because I don't want others to misunderstand or not fully understand the risk.
IT IS RISKY and often leads to DEATH.....
It can be done, however, I don't recommend it-especially to new keepers. You have a lot more risk involved-vs-success.....
That said, you can either destroy the nest after they spawn or leave it-Its up to you on how much risk you are willing to take.
Remember, once the male has a nest of eggs-then fry to protect-he will usually become extremely aggressive and if your tank isn't suited-he might kill the female and if he doesn't, by her spawning on a regular basis-(
usually about every 3-5 days when they are kept like this IME)-it can shorten her life span.