<iframe class="video_groups"  width="100%" height="100%" src="<?php echo get_post_meta($post->ID, 'mytextarea', true); ?>" frameborder="0" allowfullscreen></iframe>

<iframe id="player0" class="video_groups" src="https://www.youtube.com/embed/jebJ9itYTJE?enablejsapi=1&version=3&wmode=transparent" frameborder="0" allowfullscreen></iframe>
<iframe id="player1" class="video_groups" src="https://www.youtube.com/embed/HjxYvcdpVnU?enablejsapi=1&version=3&wmode=transparent" frameborder="0" allowfullscreen></iframe>
<iframe id="player2" class="video_groups" src="https://www.youtube.com/embed/6v2L2UGZJAM?enablejsapi=1&version=3&wmode=transparent" frameborder="0" allowfullscreen></iframe>

<script type='text/javascript' src='https://www.youtube.com/iframe_api'></script>
<script>
    var players = new Array(3);

    function onYouTubeIframeAPIReady() {
        players[0] = new YT.Player('player0', {
            events: {
                'onReady': onPlayerReady,
                'onStateChange': onPlayerStateChange
            }
        });
        players[1] = new YT.Player('player1', {
            events: {
                'onReady': onPlayerReady,
                'onStateChange': onPlayerStateChange
            }
        });
        players[2] = new YT.Player('player2', {
            events: {
                'onReady': onPlayerReady,
                'onStateChange': onPlayerStateChange
            }
        });
    }

    function onPlayerReady() {
//        console.log("hey Im ready");
        players[1].playVideo();
    }

    function onPlayerStateChange(event) {
        var link = event.target.a.id;
        var newstate = event.data;
//        console.log("I am " + link + " My state changed to " + newstate);
        if (newstate == YT.PlayerState.PLAYING) {
            players.forEach(function(item, i) {
                if (item.a.id != link) item.pauseVideo();
            });
        }
    }
</script>

function function_enqueue_scripts() {
    wp_enqueue_script('youtube.iframe.api', 'https://www.youtube.com/iframe_api', array('jquery'));
    wp_enqueue_script('youtube_switch', get_stylesheet_directory_uri() . '/youtube_switch.js', array('jquery') );
}
add_action( 'wp_enqueue_scripts', 'function_enqueue_scripts', 0, 10 );