The teen was suffering from alcohol poisoning, according to court records.
The three, arraigned Friday in Central District Court in Worcester, are accused of not doing anything for hours after the teenager under adult supervision drank a liter of whiskey and passed out, court records show.
The teen was found unresponsive, naked in the fetal position on the floor with his face covered with vomit, according to court records.
Robert K. Heneghan Jr., 37, of 116 North St., Apt. 2, Ware; Robert K. Heneghan Sr., 66, of 118 Elm St., Apt. 10, Millbury; and Kevin Heneghan, 40, of Clearfield, Utah, are each charged with reckless endangerment of a child.