Nick Jonas had to dodge an uninvited admirer at a Sweet 16 birthday dinner for longtime friend Blair Croce, the daughter of CiCi’s Pizza founder Joe Croce, at Buddakan in Chelsea on Thursday night. While brother Joe Jonas brought a date to the party, Nick showed up solo. But spies told us Nick had to avoid a young female diner at another table who tried desperately to get his attention. “She was lingering around his general area, trying to get a good look at him and Joe,” a witness said.