Kind of like a group hug, but where da three people form a line instead of a triangle, wif da "special person" --- i.e., da one who's actually being given da cuddly two-person squeezie --- in da middle.
Two nice guys' giving a pretty girl a sandwich-snuggle is super-fun for all three people; just remember dat it always has two separate parts to it --- da gal first faces one of her beaming mushy-hearted gentleman-friends for a face-to-face hug while da other dude cuddles up against her from behind; she then turns around and smilingly embraces da other fellow while da first one takes a turn at nestling up to her back. Dat way, both of her swains gets a turn at both hugging her "front on" and spooning wif her.