Change is not a one shot adjustment in most cases. Nor is it necessary that a person gets it perfect on the first try. There are a number of reasons why the result so far is what you have stated. These include:
1) Over-expression of the urge due to previous suppression/repression and this would account for an array of, or variety, of different expressions and motives for so doing. These can be anything such as: images on how to be a man, self-image based on peer competition, a desire to get back at a parent, modeling after a promiscuous father, a substituted manner of getting a mother who nurtures, etc.
2) Acting out with apparent permission of the therapist’s intervention and this can come from accidental, purposeful, or unconscious motives of the therapist.

Both of these may have been prevented by avoiding interventions simply aimed at the removal of a symptom instead in favor of and intervention based on the whole-person assessment. This comment is not meant to be personally directed to you – but in fact, this sort of outcome is a great example of why therapy should be restricted to licensed therapists with graduate degrees in the mental health fields – as it shows how well-meaning interventions aimed at symptom removal can overlook greater issues.

This case perhaps indicates that his previous avoidance is, in part, due to not associating the wisdom in his Adult judgment during matters of sexual behavior. The next part of therapy needs to help him do so.

Now all that said, HE CHOSE how to use his body and you could not make that happen and should not be blaming yourself. You should not assume responsibility for his choices. The fact that he didn’t tell you he wanted to have sex with 2 women a night sounds deceitful in a fashion that hurt your own sense of confidence in therapy. I would share that with him.