Hmm...I'm more confused now lol

I was told by a person in dc offices that even if my husband stayed home with our child as a sahd, I'd still only be allowed 3 dck's as it's 4 per house. So why is that different than a parent coming over for a play date?

Like I said, I've done play dates before and even though I've never thought or worried about it, I now wonder if that puts me over??