I have to tell you that Maggie and I (Lilly was there too) had a bed time at the park on Monday night, and we went right back Tuesday. Have you ever played with his food or water bowl when he was a pup and when he was eating? Seriously, try that, that will teach him that it can be taken away at any time and that he need to learn how to share. Even though he's never done that before, he still need to know how to share at all times. I did that with Lilly and Maggie, still do at times, play with there food while there eating. I know that sounds silly but it works.