Fake a fear of flying
Maybe this fear is real for you in which case, even better. When the plane starts to rumble and pick up speed on the runway, close your eyes and squeeze your seatmate’s hand as the plane is taking off. Do it impulsively, as if you couldn’t help it! He’ll find it cute, and it’s something you two can laugh about after. Plus it’s already set up a sort of protective position for your seatmate—a position guys love to be in.