There's a new man in Amanda Seyfried's life: New York real-estate executive Andrew Joblon.
The two have been dating "for about a month," a source tells PEOPLE. "They are calling themselves a new couple."
Tuesday night, the couple looked cozy at the Eric Trump Foundation's 5th Annual Golf Invitational & Gala at Trump National Golf Club in Westchester, N.Y., which benefited St. Jude's Children's Research Hospital. Joblon serves on the board of the Eric Trump Foundation.
An observer says he sensed "they had great chemistry" and "were great together."
At the event, Bret Michaels performed, donated $25,000 to the foundation and asked partygoers to match it. Seyfried stepped up and matched his pledge.