I feel like my girlfriend and mother crossed a boundary
It sounds like your GF and mother did something bad, but has getting angry ever worked out well for you?
Yes it has. I stood up for myself before and they knew not to do it again.
If people make you uncomfortable then you should set boundaries. Try to stand up for yourself but not get angry. Anger doesn't work all the time.
Nah they are crossing a boundary.
Since you know best, I think you should do what you should do. I just know that anger tends to create irrational and illogical reasoning, so I want you to know that at least before you proceed with your plans.