We have met friends who have been in the lifestyle for over 20-30 years. It can work as long as there is honesty and security. One has to know the difference between commitment and recreation.
I met a wonderful man through onlinebootycall.com (please don't laugh - I wasn't really looking there). We had very open conversations from the beginning, and he learned of the hobby early on also.
Some people are just not wired for monogamy, despite the best intentions. I know where my heart is, but a girl likes some strange at times, too!