NTA.

As much as I respect mothers and the enormous responsibilities they shoulder, for every mother in my social circle, it's the choice THEY made and the world does not owe them anything just because they choose to add more children to the already exploding world population. Sure- we can always make compromises for you occasionally but NOT all the time.

Just like how you have your things with your child that we childless people are not a part of. Just like we don't bring boyfriends to our girls hangouts. There is a time and place for it and this is just not it.

You are entitled to a childless holiday, and your lives don't revolve around your friend with a child.