Is she purposely breaking condoms?
When I would have sex with my now ex girlfriend it was always fantastic until the very end; what were up and down hip thrusts became back and forth thrusts whenever she sensed I was climaxing. It felt like she was trying to tear my dick off and the condom would break. This happened 3 times in a row. When asked about it she would literally cry and make me feel like asshole for even bringing it up. I still think about it to is day, especially since she has a kid (supposedly from another guy)