Ok, thanks all for replies, but the meeting was today. The dude was ok, you could see he's from another time so to say but that's nothing to be concerned(well, except for him leaving 3 months to a remote island to sit with his ex and daughter, but I couldn't ask about that). He looks exactly like her ex boyfriend, I mean face-wise. He could pass to be his brother.
Ok, so I have a good friend, my best friend. And I started to like her, and told her so. Now she replied with "and what should I say now?" to which I said "nothing, was just being sincere". This happened almost 1 month ago.
But that is for context.
A few days from now it will be my birthday, and I wanted to spend it with my best friend, her. Yes, I also like her and yes, she knows, as I stated.
However, she managed to find a boyfriend in the meantime (it's complicated, I could say I don't like him, but this time I am probably subjective since I started liking her, he's probably a nice guy just that he's 19 years older then her... and has a child with another lady whom he visits and sits with that lady 3 months per year). I don't know him, I've never seen or talked with him, he's never seen or talked to me. Only know him from stories and I presume he knows me the same if she told him stories of me.
So, ignoring this, I invited her to a sort of get-together for my birthday. I only wanted to invite her. So today we talked on phone and she asked if she can bring her new boyfriend. And I said no. And she said something like "so what am I going to do, leave him home?" and I said yes (lol). In the end after a bit more chat she convinced me to think more about it. Afterwards she sent me a message sort of like "you're so strange sometimes".
So I stood and thought. It's my birthday. I don't know this dude even from talking or saying hello once. I wanted to get along with my best friend whom I also like and she knows it... yet she wants to bring her new boyfriend. Whom i didn't invite.
On one hand, I don't want to invite him because of those reasons. On the other hand however, I still need to give her her christmas gift (she was gone to country so couldn't give it to her earlier) and I know that would make the dude think about the relationship.
What am I missing?
Edit:
I'm turning 23, she's 24 almost 25, he's 43.
Though my train of thought is similar to that of people saying I should stick with my original decision of saying no to him, the other people brought a good point, which is that I don't know him, but I'm best friends with her, so it would be nice to meet him and see if he is nice or not. Overall I didn't think this idea would create the same arguments between people as the ones I have in my head.
Still, it would be mature of me to invite him. If he's a dick to me here at the get-together then... well, hope that happens. If not, then it's good.
I was thinking of inviting only good friends, however... my other 2 good friends are busy, one is at the country visiting family and one has some work stuff. So yes, this was going to be me and her. But it wasn't so I could make a move or something. Though I admit I passed the state of liking her fully from her response in december to a state of "I don't know if I like her as a woman or a sister I never had", maybe it wouldn't have been good to be only me and her for she doesn't know that yet.
And yes, maybe I should be more direct and honest about that to her too... though she needs to be the same towards me, which she was not really in this situation, as yes, I did think she invited his boyfriend more as a shield. So we were both in the wrong here.
Overall, thanks for help all. I decided to tell her it's her choice if she wants to come with him, I don't mind either way.