Spearman and the Witch are partners, and the two are often seen together. It can be inferred that the two are very close friends.
Spearman possesses some dislike for Goblin Slayer, due to the latter's appearance and personality. He always grumbles about how he can get Guild Girl's attention when he himself can't. Despite this, he doesn't genuinely hate the fellow adventurer as he was the first person willing to help Goblin Slayer protect Cow Girl's farm. It a running gag that he can't recall Goblin Slayer's face.
It seems apparent that Spearman has shown some sign of infatuation with Guild Girl.