No regrets at all... now. But there were some times that I felt regret... like when I got caught fucking around. Or having to explain why I got a lap dance on the occasion that I go to a strip club. But that negative (getting caught) turned into a positive.
Since the explosion (caused by getting caught), it led to counseling, which led to discussions, which led to the open relationship, it became great. For example, I can be on this site and the SO knows about it and has even read some of the things I've posted.
It feels great to be able to do that.
I have to say that my marriage has been a real learning experience and I'm better for it.