According to this article:
The title tag and meta description are merely suggestions for what the search engines should display in the results. Google and Bing and other search engines are under no obligation to display exactly what you want them to display.
So it’s really up to the search engine. In Bing it looks like this:
You could try changing the meta description to use different words. Maybe Google doesn’t like that you use “El mejor foro de viajes” when there is another site that says “El mayor foro de viajes”. I’m just guessing here though, I’m no SEO expert