Into The Rift (Bloodlines Book 3) MM

Caught and sent home in disgrace, he is on a ship bound for Tygeria with his uncle, Prince Rakkur, when they are attacked by the dreaded Pton and taken as hostages. On the ship, he meets the enigmatic, gorgeous alien Lord Dominiko. He quickly falls in love with his captor, rescues his uncle and then things begin to get really complicated. 

Lord Dominiko is your typical Pton nobleman—embroiled in court intrigue, surrounded by enemies, involved in numerous affairs, and completely jaded with his life. He never expects to meet a beautiful young princeling who will turn everything he thought he knew on its head and enlist him in a crazy scheme to take terrible risks, commit amazing feats of bravery and make huge sacrifices to help others and achieve a noble goal.

If the two of them can pull this off, everything will fall into place. They might even save the universe. Fingers crossed, anyway.