I love my stepkids, but have no decision-making ability. Is my role just to get the short end of the stick all the time?

Dear Anna, 

Before my partner and I started dating, I was a family friend for years so I’ve known my stepkids for a long time and we all have a special bond. I’d even say we all love one another. 

Now that we live together, my biggest challenge is navigating what my role is supposed to be with my partner and his kids in regards to our new family structure. I totally understand that mom & dad need to make decisions together regarding the kids… but where do I fit in?
 
It feels like on the one hand, my partner wants me to be his teammate, a real partner. Until he doesn't. Then he talks about how it's up to him and his ex to make certain decisions and suddenly, I'm just there to bounce ideas off of or give my opinion (take-it-or-leave-it). I feel very disempowered. A lot of important decisions are things that involve his kids or his ex. So any collaboration and decision making with my partner feels either small (i.e. what activities we do together) or if my partner wants to (or remembers to) include me in the discussion. Even then, the weight of my input is gauged by my partner. The final decision, for his side at least, is all his (they are his kids after all).
 
I'm not okay with so much uncertainty and having so little say in things that affect my life too.
 
Am I just supposed to accept that being a stepmom means I get the short end of the stick? You can have the responsibility and the work, but not the authority or decision-making? At least I get love, many stepmoms can’t even say that, right?
 
Sincerely,
 
Sick of Drawing the Short Straw

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