Every time I yawn around my girlfriend, she would have the idea of just poking me in the stomach and, thus, totally interrupting the satisfaction I try to get from a natural yawn and she has done this since the beginning of our relationship. Fast forward to 5 months later - Now every time I yawn around her, she doesn’t have to poke me anymore… because I developed the habit of flinching in fear of her poking me which, ironically, interrupts my own yawns.