[When he feels Raph look away, Mike hazards a look in the other turtle's direction.]

I'm not ashamed of him, if that's what you're thinking. It's just...it's Raph's business, and well...he'd probably kill me if he knew I was talking about him behind his back.

[Why yes, he did choose those words specifically, and yes he is smirking should Raph turn back to see if he's serious.]