Not everyone is comfortable and wiling to be limited by the expectation that we can all find sexual and emotional fulfillment in a relationship with one single partner.
For those who prefer to live in polyamorous relationships, there are some specific challenges as well as particular joys. If it’s working well for you then you probably don’t need a therapist with experience in assisting those in polyamorous families, but you may find it helpful to work with someone who is not totally surprised by your situation.
If the challenges start to outweigh the joys, then working with an experienced therapist can help you and your partners to find new ways forward to fufillment and contentment.