Jack McCain and media personality Julia Allison have called it quits. The 25-year-old son of former presidential candidate John McCain was set up with Allison, 30, by his older sister, Meghan, in November. They moved in together in early March but broke up this month after Jack, a military man like his father, learned he would be stationed in Guam for three years starting in September. “This is an amicable heartbreak,” Allison said in her blog, NonSociety. “As silly as it feels to write that out. We will stay friends, absolutely.” She declined to comment to Page Six.