Kira just tasted the sweetest beer he ever had in his entire vampire life. Marceline made it happen.
She didn't know what had gotten into her but she just felt the need to satiate her desire, thinking of a unique but exciting way of drinking a beer.
It was Kira's fault to begin with. He unknowingly seduced her by touching her lips and saying some compliments, fluttering her heart.
Her action was only intended to transfer the beer into his mouth through a quick kiss, but it didn't work out that way as Kira's hand began to move, grabbing her head and crushing her lips in a full-mouthed kiss.
The feeling of his mouth against hers had her body deliciously electrified. He consumed her as if his mouth was unashamedly hungry for her sweetness.