"Oh, bless your ickle cotton socks. There's nothing 'little' about my ego, and trust me, when it's as warranted as mine is? It's harder to hurt than you might think."

But he did enjoy it when people tried. When they weren't successful, at least - and even if they were, if they were attractive enough. He was still more amused than at all bothered by Meg, though, whatever her intentions towards Castiel. He was reasonably confident that if shit did go down, Castiel could handle it - and if he couldn't, someone else would. So naturally, continuing to be a smug, unhelpful asshole was still the most appealing option here.

"You ever built a gazebo before, honey?"

The derisive 'because it doesn't look like you have' was strongly implied, regardless of whether or not it was true. He was here to mock, after all, not to provide a balanced critique.