Here is the OP's dilemma:
The OP hasn't seen her best friend for years, but they maintain their friendship:
The OP invited her friend to visit her and offered to help financially:
So, when Anna's visa got approved, the OP proceeded with their plan for summer:
But Anna's boyfriend contacted the OP and scolded her for not including him:
The boyfriend is a stranger to the OP
That should be Anna's break, perhaps she wants to go alone
Another Redditor agreed
He didn't have the right to call the OP
It's a girls' trip, he's not wanted
Anna should think about her boyfriend's character
Redditors told the OP she was not in the wrong for not inviting Anna's boyfriend. She wants to host her best friend, and the boyfriend is a stranger to her.
Let alone paying for his trip. If he wants to go on vacation, he needs to organize and pay for it himself.
He didn't even have the right to call the OP but berated her. If he has some doubts, he should talk with his girlfriend.