Partners best friend

Am I being unreasonable? Everytime we make a plan to do something my partner asks his best friend to join, it’s like the first thing he says “I’ll ask … if he wants to join” which okay I don’t mind but a lot of the time it’s things we could do as a family or nice days out. Well for my partners birthday I said we could drop little one off at nursery and go for food and have a Christmas shopping day together, once again he’s invited his friend and when mentioned his friend said he didn’t even know I was going he thought it was just him and my partner. Which kind of upset me even though I’d made the plan. Now for his birthday I have also booked to go see a band we like, I originally booked just us two but one of his other friends said his girlfriend really likes them too so I invited them to join as it’s like a double date so we can still have couple time rather than me feeling like a third wheel. My boyfriend doesn’t know yet as it’s a surprise but now I’m worried he’s going to feel bad for his friend being left out and want to ask him and I’ll feel like a spare part on what’s meant to be date night…. Any thoughts? Am I being unreasonable? I understand his friend is single so he doesn’t want to leave him out but surely we need couple time…