Well, you can keep it in. You can stop forcing it out with your tongue. Obviously you're having a problem doing that, but you can. You just aren't. But of course if you weren't eating at all you'd be dead, so you are keeping some of it in. So why are you doing this? Are you suffering from body image issues? Anxiety? Got any ideas why you might have decided to start doing this? If it's really something you have become compulsive about and need help with, a therapist can help.