Unlike child support, spousal support is often very difficult (if not impossible) to modify after the divorce is final, so getting it right the first time is a must!
Are they officially divorced? If so, what does the decee say about spousal support? Many decrees state that both parties agree to waive it forever and if your boyfriend's does, his ex is out of luck. If it says spousal support is reserved, that means it can be revisited at a later time. But as the other posters said, a 3 day marriage, prison and then divorce 4 months later does not make anyone a good candidate for spousal support, but he will still have to go to court if the courts allow the ex to file.