AITAH for refusing to let someone join a holiday with my friend group?

AITAH for refusing to let someone join a holiday with my friend group?

My college friend group (6 guys, 4 girls including me) is planning our second group holiday. Last year was great.

One of the girls, G, invited Jack (a friend of P’s from home who now hangs around with us) without asking anyone. Jack sometimes creates division in the group and excludes people, and some of us weren’t fully comfortable with him coming, but it was never properly discussed.

We will soon plan this year’s vacation, so I asked the girls groupchat if the trip had been mentioned in front of Jack recently - I want to know if it is the intention to keep him involved with the trip or phase him out of the plan and deal with it later (a possibility we had touched on before). G immediately responds, ‘why?’. I found this response frustrating, because it felt obvious that I wanted to understand what the plan was. To me it felt she was playing dumb, so I responded ‘What do you mean, we are ready to book early next week; its relevant’. She responded ‘duh but I didn’t know what you were implying’ This group of girls, often particularly G, is supposed to be my closest friends at college. I respond ‘That makes it difficult for me to talk about it’ (makes it awkward). She responds she ‘isn’t a mind reader’. 

I respond with voice notes effectively saying (assertively) ‘Is he coming to the arrangements or not’ (G spends a lot more time with Jack than I do). I go on to ask ‘why is this awkward to talk about, I really like Jack and I’m not sure why it is now SO difficult to have a conversation about the holiday,  he shouldn’t have been asked. Im finding it frustrating that you (G) are not allowing any space for conversation about this, because you are making it political when the decision for him not to come should always have been logistical’. I say her pretending not to understand makes me uncomfortable because I am forced to be confrontational when it shouldn’t have come to this. B hears these voice notes, and agrees with my assertiveness. G’s response to me trying to have a conversation about his attendance (her putting her back up, acting clueless etc) makes me certain I don’t want Jack there. She continues to be defensive in the group chat, passive aggressive and defensive - something I find ironic considering that this entire issue was caused by her. I can’t use P’s similar frustration with Jack’s invite with G, as Jack is P’s friend from home and it would put her in a bad position as G is clearly willling to defend Jack.

G later said my tone was rude and aggressive. AITA for being confrontational when I felt she wasn’t allowing a discussion, and not wanting Jack to come? Ultimately, I suppose I had hoped that we would be able to have an open conversation, but it got awkward really quickly and I found G’s lack of receptiveness to force my hand. I feel she was defending Jack in some way, in response to her making the issue emotional rather than practical.