Conclusion
Although there are not nearly as many female exhibitionists as there are male ones, they both share the same root of their problem. It is self love. It is a desire to have their bodies admired and loved.
In the case of Phyllis it is easy to see that her body is worthy of admiration. It is also easy to see that she could get into trouble by being immodest on too many occasions.
Her husband is obviously a very loving man. She must be honest with him so that they can solve her problem together. If he would permit her to act out some of her fantasies with him, then she would not have to resort to more extreme measures.
Her husband should definitely permit her to sleep in the nude. He should also play sex games with her in which he pretends to be a stranger who is a peeping Tom. Since she is an exhibitionist, she needs a voyeur to fulfill her fantasies. Her husband could easily play the part and help her achieve satisfaction.