Boundary or Ultimatum?

I’m in the process of leaving my abusive boyfriend. Our friend group is planning a vacation, and when the hosts told me about it they said “this invitation is extended to boyfriend, will you tell him or should I?” I told them I would let him know. A group chat for the vacation was started before I could talk to him

Boyfriend and I are breaking up for abuse reasons, but friends on the trip don’t know the extent of the abuse. I told them some of the names he called me and about the holes in walls and said I couldn’t commit to a vacation where he is present.

Friends said they weren’t choosing sides, but uninvited him from the trip because it is a bridal party thing. My boyfriend was not in the bridal party, I had to fight for him to be a guest.

I feel guilty for telling my friend/host that I wouldn’t go if he did, but is this an ultimatum or a boundary?

On one hand, I didn’t ask her to choose between me and him. I stated that I wouldn’t participate if he was also participating, no hard feelings. But I can see how they might see that as a tantrum. “Pick between me or Joe”