A woman was sleeping in her Potts Point home with one leg on top of the doona, and one leg underneath it when she woke to disturbing sensation.

For a split second she thought it was her boyfriend but then she realised he would never do anything like that.

It was 3.30am and a stranger was holding her bottom and licking her anus.

She turned around the see a man kneeling beside her bed and when she slid her hand across the bed she realised her partner was sound asleep next to her.

The woman dug her fingernails into her partner's arm and said, "Someone is there".