Displaying everything from a SQLite database using flask, jinja, python, html

I'm new to using Flask and Jinja for creating websites. I have these lines of code:

<h1 align="center">Feed</h1>
<ul class="list-group list-group-flush" id="feeds">
{% for my_feed in user.feeds %}
  <li class="list-group-item">
    <div>
      <b class="pull-center">{{user.first_name}}</b>
     <p class="pull-right">{{my_feed.date}}</p>
     <p>{{user.email}}</p>
    </div>
   <br>
    {{ my_feed.data }}

This though only displays me data pulled from currently logged-in users. What I'd like is to see on this page every post from every logged-in user.

I don't know how to do this. Do I need to change my Class (Feed) to make it MANY:MANY. relationships? Or does it suffice to change my little code above?

I want for everyone to be able to post but also read what everyone else posted. I have the code function like this:

@views.route('/tweets', methods = ['GET', 'POST'])
@login_required
def tweet():
    if request.method == 'GET':
        my_feed = MyFeed.query.all()
    elif request.method == 'POST':
        my_feed = request.form.get('my_feed')
        if len(my_feed) < 1:
            flash('Tweet is too short!', category='error')
        else:
            new_tweet = MyFeed(data=my_feed, user_id=current_user.id)
            db.session.add(new_tweet)
            db.session.commit()
            flash('Tweet added!', category='success')

    return render_template("tweets.html" ,user=current_user)