User blog:Sohatsu/Fairy Tail manga chapter 425: Natsu's motion sickness

Natsu gets terrible motion sickness in all the vehicles he rides in. But in chapter 425, in the scene in which Natsu and Lucy are travelling to Sabretooth, Natsu is riding on some animal, yet he is perfectly fine. Is it because he is riding on an animal? Or is it that he simply forgot he had motion sickness?