Session.set inside lib directory in Meteor

I have my iron-router code in my top-level lib directory in a file called routes.js. In that file I make calls to the front-end Session variable, specifically inside my onBeforeAction method like so:

    Router.map(function () {

      this.route('homeTemplate',{
        name: 'homeTemplate',
        where: 'client',
        path: '/',
        load: function() {
        $('html, body').animate({
          scrollTop: 0
        }, 400);
        return $('.content').hide().fadeIn(1000);
      },
        waitOn: function() {
        return Meteor.subscribe(COLLECTION_NAMES.PlayerCollection.value);
      },
         onBeforeAction: function(){
           Session.set('active_menu_option','home');
           this.next();
         },
         onAfterAction: function(){
        },
        data: function(){
          return {active_menu_option: {'home':'active'}};
        },
        yieldTemplates: {
          'jumbotronTemplate': {
            to: 'jumbotron'
          }
        }
      });
});

Is it kosher to call/use the Session variable in this setting? I seem to be getting wonky/non-deterministic behavior.