Barack Obama was spotted celebrating inauguration weekend in Washington D.C., on Saturday night without wife Michelle Obama. Sources spotted a jovial Barack at a dinner party at Stephen Starr’s latest Beltway hot spot, Osteria Mozza, on Saturday night sans the former First Lady, who we reported is skipping the inauguration. We’re told the restaurant was gobsmacked when the cool former prez made his way through to a private dinner party upstairs. And while we hear, “he was very nice,” a source added, “he didn’t stop and take photos with people.” Barack joined a small group that included President Biden’s White...