Fraternizing with guests means having conversations with them, and getting to know them. This usually happens at a party or during dinner.

British English: Fraternising American English: Fraternizing

In Narnia, fraternizing means spending time or socializing with beings from a different realm or species, often in a friendly or informal manner. It typically involves interacting with creatures or individuals outside of one's usual social circle or group.

Treason, homosexuality, moneylaundering, fraternizing with enemy,

Ron Told Hermione that she was "Fraternizing with the enemy".