I'd been pestering DH for DC number 3 for a while & whilst it was never an out-right no he'd rather stop at 2 & always changed the subject or said we'd discuss it in a few months. Earlier this year our cat died & we agreed to get another one - DC & I wanted to get 2 but DH wanted 1. One night we were having the 3rd baby debate & I could see he was less & less keen & beginning to get a bit annoyed at my constant talking about it so I said "if you agree to getting 2 cats I won't mention the baby thing again". To which he agreed & we got 2 cats. Of course my baby yearnings didn't magically disappear with the extra cat but I decided not to bring it up for a few months.
We were visiting his sister this weekend & she mentioned us having more children (in a friendly 'I know your keen but hadn't you better get a wriggle on' way) so I said I'd still love another one but DH isn't keen. He overheard & got really arsey saying I'd made a promise never to discuss it again once he'd agreed to getting a 2nd cat. She roared with laughter & couldn't believe he would plan his family around a couple of cats & that he was crazy to think I actually meant it when everyone knew how desperate I was for another baby. He was in a right huff & wouldn't discuss it other than to say we are NEVER having any more children now we have 2 cats. I (flippantly) said fine we'll get rid of the cats to which he said fine & stomped off. 
So, all very childish but is DH being unreasonable for thinking I honestly wouldn't want another baby when we got the 2 cats or am I for making & then wanting to break this promise? And where do we got from here....?