London, Dec 28 (IANS): Actor Robert Pattinson's sister Lizzy is reportedly not pleased with his descision of getting back with Kristen Stewart, and has even fought with him over the matter.

Pattinson, 26, reconciled with Stewart even after she was found cheating on him with director Rupert Sanders. However, Pattinson's sister was not convinced with his taking back someone who hurt him so bad, reports thesun.co.uk.

"The rows kicked off on Christmas eve when protective Lizzy had some words with Robert about getting back with a cheat," a source said.

"They were out drinking in Barnes, where Rob grew up. Lizzy was giving him grief about taking Kristen back and said she's always hated the way he's been treated by her," the source added.

Stewart, 22, decided not to accompany Pattinson for his family get-together as she is scared of them.

"He and Kristen spent the festive season apart partly because she's terrified of facing Rob's family," the source said.