Blended families start when a couple falls in love and at least one person involved has children from a previous relationship. Many blended families have long-term success and happiness together, but there are cases where they end in divorce as well.
If you have been the stepparent to your spouse's child for many years, they may feel like your own child. Do you have the right to request shared parental rights and responsibilities, especially if your ex is not enthusiastic about you staying in the life of their child?
Did you complete a step-parent adoption or take care of the child on your own?
Some stepparents choose to adopt their stepchildren. This process usually involves a living parent giving up their parental rights or a deceased biological parent. You typically need the approval of your spouse and for the courts to determine that the adoption would be in the best interest of the child. If you have formally adopted your stepchild, you have all the same parental rights and responsibilities as any other legal or biological parent.
If there were circumstances where your ex was not able to fulfill their parental obligations, possibly due to medical issues or incarceration, you may have the right to ask for shared custody if you were the sole person fulfilling the duties of parent for at least 180 days or longer, possibly due to your spouse's illness or incarceration. Barring those two very specific situations, it is unlikely that you can request an equal share of parental rights and responsibilities in a divorce.
Visitation may be a more reasonable request for a stepparent
Although the courts may not recognize you in the same way they recognize the biological or legal parent of the child, that doesn't mean that your relationship with the child isn't important to them. Provided that you can show that you have a positive relationship with a child and that your presence in their life will have a net positive impact, the courts may be willing to award stepparent visitation in order to help preserve a relationship that has been important to the child.
It will be the best interests of the child that guide the decisions the courts make, not just the desires of the parents. If you know that you can be a positive influence on the life of your stepchild, asking the court to acknowledge this can benefit you both.