The rush can be addictive, though, so let's hope that your husband can give the rush its due and then steer clear. He will need some help, from both you and the therapist. Any sign that he is just nodding and saying whatever will get him out of there the fastest, and I'd start worrying again.
Interestingly, there are 12-step groups not just for the more obvious "sex addicts" but also for "love addicts." They are meant for those who use "love" as a drug to lend meaning to an empty life or excitement to a dull one, not to the ordinary person who, glimpsing something shiny, follows it through the faerie wood and then, realizing he's been briefly enchanted, returns, chastened. Still, understanding that "love" (these are not quite scare quotes, but certainly sneer quotes; I don't think what these seekers are finding deserves the name) can be so powerful a drug may help both of you to forgive him.
Got a salacious subject you want Andrea to discuss? Ask her a question!
Also, Andrea is teaching! Contact her if you're interested in (sex)life after baby classes. Her new blog is at www.gogetyourjacket.com, but don't look there for the butt sex. There isn't any.