I think he just hates buttons and has all shirts custom made to exclude any form of buttons. Maybe he swallowed many buttons as a child, and must have been thrashed by his amma for being such a disobedient child, laying his hands on forbidden fruits. His revenge must have started from his childhood. Button revenge! And day by day, his hate for buttons will grow tenfolds until one day, all button will break loose and the shirt will disappear. His revenge on girls will be complete, for all of them will faint and probably vanish in thin air.