A source confirmed their break-up to PEOPLE after Bendjima was photographed getting cosy with another girl in Mexico.
TMZ published images him with his arms around Jordan Ozuna, who has previously been linked to Tyga and Justin Bieber.
E News! reported that the pair struggled with their relationship since returning from their European vacation.
"Kourtney and Younes have been arguing since coming back from their big Italy trip and have truly not been getting along," the source said.
They added: "Kourtney is upset but she is trying to focus her energy on other things and stay busy. Kourtney doesn't plan on calling attention to it publicly and wants everything to blow over. It's upsetting to her.
"There was a huge chance they were going to get back together and they were working on things. But now that these photos surfaced, things are definitely over."
Bendjima seeminlgy appeared to comment on their break-up via Instagram, saying: "They really want me to be the bad guy. F— your Hollywood bulls—, can’t have fun with your friends no more.”