router.js

var counter = 0;
Router.route('/messages', {
  waitOn: function() {
    var toWaitOn = [];

    if (!Meteor.user()) {
      return toWaitOn;
    }

    function getOtherMember(member1, member2) {
      return member1 === Meteor.user().username ? member2 : member1;
    }

    MessageSessions.find({ members: Meteor.user().username }).map(function(session) {
      counter++;
      var otherMember = getOtherMember(session.members[0], session.members[1]);
      toWaitOn.push(
        Meteor.subscribe('message', otherMember),
        subs.subscribe('profilePic', otherMember)
      );
    });

    console.log(counter);

    toWaitOn.push(Meteor.subscribe('message'));

    return toWaitOn;

  },