Macaque is your boyfriend, He loves you more than the whole world.. So of course he would get Jealous.

He eyed the boy you talked to, His eyes forming a glare as he huffed, his tail flicking around with slight irritation. "Whats so good about him..?" He whispered to hismself snarkily. Before moving to stand by your side, Wrapping an arm around your shoulder- bringing you close to him in a possesive manner as he glared at the boy before him and you.