<human>: We have been together for 1.5 years and she is very close with her ex. They vacation together and meet up several times a week to exchange the kid or just hang out. We live together in an apartment, her, her kid [8], and me. 

She got herself into some debt that she is very antsy to get out of. He ex makes more than 100K a year and pays her to take care of the kid so she doesn't have to work. We recently got talking about the future and how we are going to share finances, which we have not worked out very well at the moment. I mentioned that we shouldn't be splitting things 50/50 since the kid lives with us and if she needs financial help she should be looking to her ex. I also said that I am not interested in paying for the child in general when we go anywhere on trips etc, but I would be very open to sharing expenses with her and for our future family. 

This got her very upset, she called me a monster, said the two of them come together and if I share expenses with her it has to include her child. SHe then broke up with me and does not want to talk again.

I fail to see what got her so upset as I think that is quite reasonable not to pay for someone else's child. I'm very sad about this and don't know where to go from here.

Condense the text into a few key points
<bot>: My girlfriend broke up with me because I don't want to pay for the child she has with her ex who is rich and very involved.