By George P. Hassett

A Somerville couple woke up to a surprise on Sunday morning: a complete stranger, passed out drunk in his underwear on their living room sofa, according to police.

The Linden Avenue couple and their six-month old child left the home and called police after they saw Nathan A. Willette, 21, of 285 Bell Marsh Road, York, Maine sleeping in their living room.

“They did not know this man and had never seen him before,” Officer Mike Ameral wrote in his incident report.

Police said the woman who lives at the house was visibly upset by the sleeping man.

When Ameral woke Willette, he seemed disoriented, police said. When asked if he knew where he was Willette answered, “Boston.”

Police said he smelled of alcohol, had fresh scratches on his arms and legs and a head injury.

A loud, “out of control” party next door brought police to Linden Avenue on Saturday night for “drunk person calls,” police said.

Police said the home showed no signs of forced entry or damage. Willette was arrested and charged with breaking and entering in the nighttime for a felony.