Well, He's Somebody's Daddy, Just Not Yours

So, Father's Day is this weekend, apparently.  Who knew.  Anyway, apparently they have been "discussing it" at daycare, because my kid has been all about "Daddy" for days.

I've tried "we don't have a daddy at our house.  We have a Mommy.  And a Nan and a Grandpa that love us very much."

I've tried the above plus "every family is different.  Some families have just a mommy like ours.  Some families have two mommies like (name-of-kid-at-daycare)."

She's been out-of-the-blue saying "Daddies".  When we sing "Wheels on The Bus" we ALWAYS have to do the Daddies Go Read-Read-Read part.  (What, don't mommies read on the bus?  WTF?)  Sometimes I just let it go, and sometimes I try to remind her of the above conversation.

This weekend, she called my father "Daddy" from another room.  We jumped on that with "Grandpa?  Do you need Grandpa?"

Today at dinner, out of the blue she said "Daddy".  I said "we don't have a daddy, honey" and she said "Two Mommies" (from the aforementioned conversation). 

At this point, I'd rather talk about "two mommies" than "daddy".

If I just didn't have so much guilt about depriving my kid of a father, these conversations probably wouldn't bother me so damn much.  I hope I'm doing it right.  Suggestions?