At first, some nsa finders had a relationship with them. There is no comment on the fact that it is not monogamous and will not last forever. Not everyone finds it harmful if their partner wants to leave or date someone else. Well, things are vary with different people. Some adult friend finders do have hope that their fwb dating will eventually develop into a more serious relationship, so it may be sad to hear that your partner wants to develop this pof dating relationship with others.
Motivation is also important in affair dating relationships, and nsa finders choose to do so for many reasons. Some people may not want to be bound, or they just want to get intimate with some adult affair finders. Others may value the emotional connection between friends, or they may want to avoid a chaotic relationship. Some people may just think that having an FWB is a good idea for them, for whatever personal reason.
Statistically, an FWB hookup relationship is unlikely to turn into a romantic, monogamous relationship. Most people either become friends again after a year or they have nothing to do with it. One thing you need to note that it is not wrong or rare to hope that this pof dating relationship develops into a fixed one. In a relationship, people's expectations and motivations can vary from person to person. Some adult friend finders realize they want more even after agreeing to become FWB. Remember: becoming friends is an inherent part of this relationship.
You can't really predict the direction of the FWB dating relationship, which may attract some adult affair finders but setting some basic rules is definitely a good idea. In order not to harm anyone, establishing restrictions and boundaries is important for friends who have a good adult affair dating relationship. For example, you can agree not to tell each other when you meet. Or you can tell your partner that you want to be open to other people you date, as long as you feel comfortable. This will reduce your chances of being caught off guard in the future.
If your fwb dating partner does end up wanting a relationship with someone else, it's really hard not to take it personally. In most cases, you have to decide whether you want to still be in friends and mature hookup with this one, or completely cut your ties. Despite the best intentions, if you don't have boundaries then consequence that things get awkward and the pof dating relationship won't survive.