NEW couple alert: Jason Segel from CBS’s “How I Met Your Mother” had Chloe Sevigny of HBO’s “Big Love” on his arm during the HBO Emmy party in West Hollywood Sunday night. The duo drank Moët & Chandon champagne and ate Godiva chocolates and then “went outside together to smoke.” After they left the party together, another source spotted them “kissing and standing arm in arm” while waiting for their valet.