From Longman Dictionary of Contemporary Englishrun out on somebody phrasal verbto leave someone when they are in a difficult situation – used to show disapproval He ran out on her when she became pregnant. → run→ See Verb table
Examples from the Corpus
run out on • Now take Benny there and the way he runs out on Corrigan.• My dad ran out on me and my mom when I was ten.• If a guy tried to run out on them, they nailed his legs to the floor. 