Found it ! Sorry !
<div class="blog-text"><?php if( empty($post->post_content) ) {} else { echo '<span class="rsTmb">fr</span>'; the_content();} ?></div>
<div class="blog-text"><?php if( empty($post->anglais) ) {} else { echo '<span class="rsTmb">en</span>'; echo get_post_meta($post->ID, 'anglais', true);} ?></div>
<div class="blog-text"><?php if( empty($post->espagnol) ) {} else { echo '<span class="rsTmb">es</span>'; echo get_post_meta($post->ID, 'espagnol', true);} ?></div>
