They are meant to flare at each other, its courtship, try putting her in a jar/bottle inside his tank (assuming he is in the breeding tank). They should stay like this for a week or two. he is ready when building a bubble nest, she is ready when you can see her ovipositor tube, please please read ALL the information that is available on this site, it is very well made and he is a professional:
There are links to the 6 specifics at the bottom of the page. good luck!