The 20-year-old man, who was said to have drunk a large amount of gin, was found covered in blood at his home in Salisbury, Wiltshire. His 17-year-old girlfriend had ended their 'fairly tempestuous' relationship earlier in the evening.
He was arrested under the Mental Health Act after a cab driver who had been called to the house alerted police. Inspector Stuart Hardy, of Wiltshire police, said the man had taken the knife to his chest to 'cut the tattoo out to remove all trace of his girlfriend'.
He added: 'Police attempted to get him to hospital to have stitches, but he refused. He was subsequently brought to the police station for his own protection.'
After being seen by a doctor, he was allowed home without charge.