>>130216300In the Franquin era the main characters weren't allowed by the publisher to have relationships, so seccotine was first a pest and rival and later an esteemed helper and colleague.
Fournier started the romantic angle and summed up the way it's generally been since then as follows: Fantasio pursues girls, who ignore him and pursue Spirou, who politely ignores them. This lasts until Luna Fatale where he finally displays some interest.
Tarrin ships Spirou with seccotine but that's a Franquin fan thing, also simultaneously makes gay jokes about the main duo, M&M drew Spirou kissing Seccotine in their final book but it's not really supported by context (especially since one of the final twists is who his true love has been during the whole M&M run). Yoann & Vehlmann do... whatever the fuck they do. And of course there's the WW2 spinoff where Spirou's teenage love is a jewish girl.
