Aunt Mary and Uncle Jeremy bought Ben this little onesie (in case you can't read it, it says "chubby") for Christmas. After hearing the onesie said "chubby", Ben was very concerned about his weight. He tried to pose for the camera by sucking in his stomach in order to look less chubby. (Did he learn this trick from you Aunt Mary?)
However, after his mommy explained that "chubby" was a good thing with babies, Ben relaxed and was less concerned about the camera.