Wordpress Posts per page if condition met

Wordpress Posts per page if condition met

I have a custom post type called activities and a number of standard pages
that are different countries. Each country has a number of activities that
are available. The user needs to add a range of different activities, and
then choose what country each activity is available in.
Using list pages, I have a dropdown listing all pages in the activities
custom post type. The user is able add a new activity, add the content and
select what country(page) this activity relates to. On that particular
country page on the front-end the available activities are listed.
For each country I only want to show 3 activities. I do the standard loop
getting all custom post types for activities. I have to check whether the
postid of the page chosen in the drop down menu matches the current page,
and if it does show the activity. Using the standard posts_per_page isn't
working, as it only grabs three posts, then does the conditional statement
on those to see if any matches the current id.
I guess what I want to happen is to have the posts_per_page only apply to
activities that actually match the criteria of having the country page id
matching the id of the country selected in the activity.
global $post;
$postid = get_the_ID();
$args = array( 'post_type' => 'activities', 'orderby' => 'date', 'order'
=>'ASC','posts_per_page' => 3);
$loop = new WP_Query( $args );
while ( $loop->have_posts() ) : $loop->the_post();
$country = rwmb_meta( 'rw_activities_pages' );
// this is the drop down list of pages. It gets the ID of the country page
chosen
$currentID = get_post($country);
$currentTitle = $currentID->post_title;
if ($country == $postid){
// if the activity country id matches the current page show the info
echo get_the_title();
echo $currentTitle;
echo the_content();
}
endwhile;
wp_reset_query();
Any ideas would be fantastic, as I have a couple of custom post types that
do a similar thing!
Thanks in advance,
Rich