Nevermind, I find a way.
Here is my code in case someone would do it:
<?php
$terms = get_field('categories_a_afficher', 'option');
if( $terms ): ?>
<?php foreach( $terms as $term ): ?>
<div class="category_list">
<h2 class="fond">
<?php echo $term->name; ?>
</h2>
<a href="<?php echo get_term_link( $term ); ?>">
<?php _e( 'View all posts from', 'twentyeleven' ); ?> <strong><?php echo $term->name; ?></strong>
</a>
<!-- Here the query begin -->
<?php query_posts( 'showposts=2&order=DSC&cat=' . $term->term_id . ''); if (have_posts()) : while (have_posts()) : the_post(); ?>
<?php get_template_part( 'content', get_post_format() ); ?>
<?php endwhile; endif; wp_reset_query(); // On ferme la boucle ?>
<?php //echo $term->term_id; ?>
</div><!-- .category_list -->
<?php endforeach; ?>
<?php endif; ?>
