So, I (32F) was invited by my boyfriend's (34M) mother to go a family vacation that is happening in December. I was invited way back in the spring. The trip is to Disney, it is specifically for my boyfriend's toddler aged son. My by's mom, is paying for everything for him, his ex-wife, and his son. Flight, hotel,tickets, food. all of it. When the offer was made to for me to go along, it was also offered to ex-wife's new boyfriend too. But the catch was she'd only be paying for our rooms, nothing else. Alright, money doesn't grow on trees, awkward but i get it. I declined, the job i was working meant there was next to no way i could go. Was it going to be awkward home alone while my boyfriend was at Disney with his ex-wife? sure, but what can you do? The ex-wife's boyfriend also declined going. Important context: This trip was planned from before their divorce. It's been rescheduled twice. first due to their divorce proceedings, and then due to illness. This Disney trip has been planned longer than my relationship with him. Then i changed jobs unexpectedly, and suddenly I was able to go. This change happened in late July/early June. When my boyfriend asked about me coming along now, his mom responded that it was too late, the rooms were booked and there was no room. So i'd have to pay for myself. But i decided I really wanted to be there. Boyfriend and I are getting engaged this fall. I don't want to be a fiancee left behind, excluded from a family trip. So I booked the room and my boyfriend made the decision to stay with me so I wouldnt be excluded or left alone. Here is where it all hits the fan. His mom was not happy about this. My boyfriend made it extremely clear that he would be with his son every night to put him down, and would drive over early every morning to be there when kiddo wakes up. He was going to be with his son every moment he was awake. But the fact that when his son was asleep, my boyfriend would be with me (his fiancee by then) made her furious. Her and my boyfriend have had several arguments at this point and she has started saying I can't go to the "family" dinners that she planned. I guess i'm just supposed to kick rocks by the curb until they are done with dinner? She is aware we will be engaged by that time. I haven't made a single request of her. She said I couldn't stay with them at their hotel, I said "okay" and got my own, with my boyfriend, and now suddenly everything has exploded. And she is blaming me for all of this. So am I the A-hole for agreeing to go on this trip? Edit: OR am i the asshole for because my boyfriend is staying the nights with me at my hotel? extra info: There actually is room for me in the hotel rooms, but she wants to have a 'common space'. So, in her mind, there isn't.