User blog comment:FairyRaven/Fairy Tail Chapter 392: You Must Not Forget, Review and Commentary/@comment-24800928-20140711144951/@comment-7418318-20140712070526

With the way he wears his coat over his shoulders I wouldn't be surprised if Laxus also used lots of strong cologne or something similar. :P

But on a more serious note, within the guild it was known from the beginning that Laxus was Makarov's grandson, so there would have been no need to point out a similar smell if they have it. And as I said before Ivan most likely took precaution.