User blog comment:Godisme/Eternal Flame/@comment-5894890-20130912225134/@comment-7418318-20130912230548

I guess they also have the whole "no biological family and being raised by non-humans" thing in common.

Still Godisme does have a point. Just remember how Natsu went totally berserk against Jellal because he made Erza cry, even when Jellal offered to help and now he just goes "Not our enemy? Oh then it's fine"?

With Gray I can understand the lack of reaction. For one thing he's less prone to emotional outbursts than Natsu and for another thing, he's running away from the eyeball thing when he sees Flare. Not exactly the right moment for any lengthly considerations and questions.

But Natsu meets the girls when there is nothing going on around them and he's far more of a hot-head than Gray, so a little more suspicion and anger would have been far more believable.