Up until the age of about three, I reckon kids have no understanding of what a birthday is. They definitely won’t remember if their parents grumpy friend doesn’t get them a card.
Get the kid this card. The parents will see the funny side because you are all friends (ad if they don’t are they really your friends?). Then in 20 years time when the kid is going through all the baby stuff their parents have kept boxed up in the attic they will find it. And they will have to admit to themselves that this is the funniest (and most honest) card they have ever received.