Friends feel that the reunion was really unhealthy as they have had such a turbulent relationship at such a young age, reported Sun online.
"We did everything we could to keep them apart but he was so persistent. It's really unhealthy they have such a turbulent relationship at such a young age.
"He leaves her in floods of tears constantly. She has had a really difficult year or so dealing with the tense emotions that come with dating him. We thought she had finally broken free. But he has persuaded her to take him back again. There's not much we can do about it - but we are going to try," a source said.
The 'Baby' hitmaker has had a controversial year following his headline-making tour in England, where he ended up scrapping with a photographer and had a stint in hospital.