The idea of sexfriend still facinates me. Having a sexfriend is cool, as long as you and your partner is only messing with 1 or 2 partners at a time. Having multiple partners are dangerous, to be honest.
This kind of relationship is convenient as well. You don't need to invest a lot of time in your partner, and just meet with them when you just want to have some skinships or sex. Few things to invest, few things to lose.
I guess there are a lot of people that don't really want to commit with someone, but still want to have a fulfilling sex life.
For me, I don't really get it when someone enter a relationship without marriage in sight. Isn't it just a waste of time? Waste of effort? Man, if I want to settle, I'll just enter a relationship and make it clear to my partner that I'm already considering her as a marriage partner. If you don't see me on the same light, then I guess let's just settle being a sexfriend or friends, and don't waste both of our time.
Just don't be a whore or a manwhore when entering a sexfriend relationship. Having 2 partners, then changing partners every month seems like a different thing than that sexfriend thing.
Last thing, if you are entering this kind of relationship, just make sure to make some rules and stick to it. Someone break a rule? Break the relationship. It's pretty convenient setup, but it has also some risk. And don't put some romantic feelings on it as well. You're putting yourself to a lot of headache.