Retepsian

The Retepsians are an alien species which are members of the Planetary Union.

Biology
The Retepsians are a blue humanoid race with cranial ridges and curved ears. While capable of articulating in comprehensible language, they are able to project their voices similar to a klaxon. They seem to eject a blue goo substance in moments of distress from their brows. They are sexually compatible to humans. Once a year they go through heat and they release a pheromone that attracts mates.

Culture
The Retepsians are a culture that considers turning down sex rude.

Source

 * The Orville Season 1: Episode 1: Old Wounds
 * The Orville Season 1: Episode 9: Cupid's Dagger