Is a man's sucking another man's penis considered sodomy, and what is the ruling of Islamic law on that?

The abomination of sodomy is among the greatest transgressions. No one committed it before the people of Lot, whom Allah punished with the severest torment. The Companions agreed on executing both the perpetrator and the one upon whom the act is committed. The preliminaries to this abomination are unanimously forbidden. The preliminaries of sodomy are of several stages: enjoying the forbidden gaze, playful interaction, fondling, and embracing, and finally committing the major abomination itself. Persisting in minor sins elevates them to major sins, and what is mentioned in the question indicates the malevolence of the perpetrator's soul.