-Facepalm-
...
Iroh's son is named Lu Ten, not Mako.
Mako is the name of Iroh's voice actor (In avatar: the last airbender) who died in the middle of Book Two, thus naming Mako after Mako Iwamatsu. I'm pretty sure your referring to the episode where it was Lu Ten's birthday and it said at the end of it "In honor of Mako" Mako, as in the voice actor, not implying that that was Iroh's son's name. Understand?