Hi there, The man I have been dating for 8 months wants to take a 3-4 month roadtrip with another girl.

He has had this tripped planned and discussing it with her Since August 20th.They will be sleeping in different tents and going in two separate cars.

Context on the girl: She is his older sisters best friend, she is well- acquainted with his family and they have known each other for years now, so yes longer than he has known me. I have met the girl(multiple times) and its fine shes cool but I know she knows I am not okay with this even though I have never expressed this to her.

Frankly, he has never asked me if I am okay with this trip and does know I am not okay with, he has let me meet her multiple times and has done a good job in trying to give me security on it.

The trip was supposed to happen this summer, but Co-vid got in the way. I am selfish but the amount of relief I felt was so necessary, he had a phone call with her and they agreed to do a week-long trip in the fall, but thats to prepare for them to take their 3 month trip next spring in 2021.

He did not ask me at all if I was okay with this and just informed me of their new camping plans on a phone call later that day, I was pissed and angry.

Should I just give up? Why is he so desperate to take a trip with this other chick? Why can't he find a male to do it with? Please be radically honest with me and tell me what you think.

Ultimately I don't know how to go about this please give me some perspective,advice or critique.