Well, I assume he's working under the logic that it's a suicide mission due to the fact Priderock is swarming with hyenas. He's just being realistic...but Naanda's having none of it.

:O Tsk, tsk Mega, how could you not help them?

I imagine it's because he doesn't help Naanda during Scar's reign and she's calling him out on it.

Uh oh, Mega, what did you do?!

I know...I didn't know that but that's the name I was going with for them as a couple.

They do look good, and by the way "Naaga" means "snake" in Telugu