Hope below helps. Let me know if you further questions:
Thank for posting the images on Flickr. Looks like the gang had much fun!
Step 1: You > Albums > select the album you want to make Private > Edit > Batch Edit > Change Permissions > Only you (who can see these items) > Change Permission
Step 2: You > Albums > select the album you want to make Private > Click the Share Icon on top right hand corner of the screen (curve arrow above a U shape tray) > Email > Enter email addr of Vincent, email addr for FYM, ... > Type your message > Send > OK to images mark Private.
Vincent, FYM will receive an email, and will be "allowed" to view the specific album.
Changing Permissions to Friends only is another method, but will only work for Vincent if Vincent has a Flickr UserID.