i know your situation well.... its so much like mine.

Try this, instead of calling him poppy.. call him poppy (name), it seems much more impersonal to me. Also, during convo'z say things like Nanna and (name). That way u dont have to start a fight about it but u are encouraging them not to call him poppy. I mean come on they should get the hint. Or.. call him grandpa, or gramps... alot of men arent into this so that just might fix the problem all together. If they ark up, say she already has a poppy and when she starts talking etc, its good for her to know who im talking about and who shes talking about.

I could go on forever for senarios u could use lol