Thursday wasn’t supposed to be so hectic for Malcolm Rogers. But when the MFA director missed a connecting flight from Spain, where he was visiting colleagues at the Prado Museum, he was delayed. So Rogers had to race from Logan to join Caroline Kennedy at the JFK Library Thursday. The occasion? For the 50th anniversary of the Cuban Missile Crisis, the MFA has loaned Pablo Picasso’s monumental “Rape of the Sabine Women” to the library that bears President John F. Kennedy’s name, and Rogers and Kennedy’s daughter were present for the unveiling. “We lend works of art all the time, but to find an opportunity to do something like this in the city warms my heart,” Rogers told us. He said it was the library’s idea. “They approached us — quite nervously, I think — and we said, ‘Tremendous, we’d love to.’ ” The picture, one of Picasso’s last major history paintings and a denunciation of war, will be at the library until mid-January.