Bit of context here. My SO has been friends with the girl for 6 years, they went to highschool together, they're close and they could be considered BF's. I met my SO through her, and she is also a close friend of mine.

We've known her boyfriend since they started dating so about 3-4 years. 

Now, they do this thing where we simply HAVE to spend every festive occasion together (NY for example, couple of years in a row), and we've also been taking winter/summer vacations with them.

Now, I don't exactly mind them, and while they can be fun, the two of them together can sometimes be toxic to be around, individually and  paired up, won't go into details but it can and did previously take from the vacationing experience.

Me and my SO both agree that we don't want to take our next summer vacation with them, and we tried toning their will down by saying we plan on moving in together so we can't really afford a vacation, and we thought we could just schedule a last minute one while they are already away. 

We also simply considered telling them nicely how we want to be left alone, since I don't want to deal with anyone else's baggage other than the two of us.

Are we the assholes for trying to weasel out of it, or would we be the assholes for telling them straight up, we wanna go alone? 

My SO fears that this would deeply hurt our friend because she has issues with being neglected, and would most likely take it to heart. 