How do I deal with a fiance caught soliciting phone sex online?

[Megan]

I recently found out that my partner has posted an online photo of his genitals and posed as a single man looking for phone sex on craigslist.com. I debated whether to confront him and decided to because I want to be honest about what I saw. In terms of pornography and masturbation, we have a very open relationship; I have absolutely no qualms about either of those two things. He defended his actions as just an extension of pornography and said that he had called sex hot lines before, that this was cheaper. I honestly don't care about hot lines, but he was reaching out to a specific geographic area where he could easily meet up with a phone partner. I know he isn't cheating on me; he almost never leaves the house (works from home) and we have spent the past 3 months worth of weekends out of town, with each other the entire time. It's not like he couldn't step out, though; he is an attractive man in a variety of ways (well-educated, handsome, etc.). I know he loves me and would never purposely hurt me. If I knew it would stay at just phone sex, I probably wouldn't care. This just seems like a stepping stone to something more serious. I don't want to break up in any way; we're getting married in a few months and we have planned our lives together. He has said he won't do it again and I believe him, but I don't want us to turn into a prudish couple that doesn't allow some sort of sexual escape for each other. Was I wrong to confront him about this? Am I wrong to be freaking out a little about the proximity issue?