It looks like she felt that the cock is impregnating and got hornier, she wasn't caring anymore about the cum overflowing inside her. She didn't stop at all instead she kept inside until she was completely filled. Remind me of my ex after couple of time the rubber broke she went under contraceptive cause she couldn't stop when she was feeling the sperm. We got scared couple of times for missing period.
This happned to my girlfriend and her bull too. They were so in heat that the condom broke and he came inside her... but yk what i dont even care because i know they dont use it when im not there and i love it coming home and fuck her tight pregnant pussy