Embedding You Tube video

Hi all,

If you go to https://netwerkeninbelgie.be you’ll see a post called “Het nieuwe werken” (top right).

Underneath you see some html text which is actually the youtube link.

When you click to “read more” the html text disappears and displays the youtube video correctly.

Why does the html text appear in the first instance and disappears when you click “read more”.
I don’t want any of the html text to appear.

thx
Chris