User blog comment:FairyRaven/Fairy Tail Chapter 400: Wings of Hope, Review and Commentary/@comment-7418318-20140913111541/@comment-7418318-20140913171147

You didn't, so don't worry about that.

I think it's more likely that Igneel could only feel the state Natsu's body was in, as in how hurt or exhausted he was. Maybe even sense his emotions of sadness, happiness and such, but I really don't think he could literally see and hear through Natsu's eyes and ears.

Furthermore to be pricy to every move Natsu makes would be a very severe intrusion into Natsu's privacy and unnecessary tempting for Igneel to come out prematurely, so I think he'd limit himself to occasional glimpses or completely forego this ability to see through Natsu's senses even if he has it.

Of course that's just my theory, but it does make more sense to me.