Sean Lennon turned down Paul McCartney’s invite to see him play at Citi Field in July. But for good reason — Lennon had already booked a gig at the Living Room with his band the Ghost of a Saber Tooth Tiger. “I wrote him, I was like, ‘I’m really sorry, but we are playing a show for like twenty people. Could you not take everyone in New York?’†the musician told us last week at JCPenney’s party for Charlotte Ronson’s diffusion line, I Heart Ronson. “And he wrote back, ‘I promise to leave you at least eight people.’†How generous!