now i have to go to the store and find a "congratulations on your doctor/dentist visit" cards.....

when i pick out cute little cards for liam...am i allowed to get ones that say things like "for a cute nephew who is 3!" even though technically he is NOT my nephew? or are we just telling him that he is? i'm still a little confused on that point, and i sure don't want him to feel the same confusion i feel. not just about that, but in general. i'm often confused.