Soulmates is a term that is easily been overused and not always clearly understood.     Some believe...      there is only one soulmate, who we must search for our whole lives.
                       Some believe...                   that it is a connection from a past life
that the two share.
Each person must decide these                 things for themselves...
     From a growth perspective,  we may meet many soulmates in our lifetime.
This doesn't mean we are lovers with each one, although that again is a personal choice.
The meeting and continued relationship is all about growth and the synchronicities that enable our growth on deeper & deeper levels... (some feel that enlightenment is just deeper & deeper levels of relaxation - as does the person writing this.)
However, remember that there are twinflames and there are soulmates.
Both are meaningful relationships and teach us to grow, but in different ways.

Soulmates compliment us, they are in many ways our opposites... they can become easily codependent because each one completes the other.  However, the lesson of soulmates is to both become whole people through a respectful love, plenty of understanding and an honest focus on growth. Then, we can be involved in a continually growing interdependent relationship of soulmates...  Remember: the releationship is the space in between you both and must be protected by both of you.  Nurture it, and if someone hurts their lover, it's best to also appologize to the relationship as well as the person who got hurt.
(Children are the physical form of this truth.)
Twinflames are just like us in so many ways, we think, and act so similarly and the rhythym of our lives, no matter how different the specifics are, is still very much going in the same patterns of lessons. Twinflames come into our lives to show us who we are by mirroring us, there may be some competition between the two, which may even serve the growth of both... until it doesn't.   
(This is probalby more common is extra marital affairs when the person has lost who they are in the relationship, and a twin flame comes along to remind them who they are again.)
Have no judgment of who we draw into our lives... offer kindness, recieve the blessings of our growth from facing our deepest part of ourselves through another and be honest with kindness. If we really grow, the upgrade (either the same person also upgraded through the growth you've both shared, or someone new who matches better who you are now) will be drawn to you if you keep focusing on growth and what's best for all concerned. Let love help us to find our way through... letting us see who we are by who we draw in (friends as well) and that we may all be made better because of having shared love, for that is surely why we are here.  

 
A path to interdependency: Transparenting           
Transparenting Tools & Understandings