Why does Count Almaviva send Cherubino away to join his regiment?

Count Almaviva decides to send the page Cherubino away to join his regiment primarily as a way to remove him from the castle after catching him in compromising situations with women.

The Count’s motivation stems from his jealousy and desire to eliminate a romantic rival. He first vows to make the boy leave after discovering him hiding in a chair while the Count was attempting to solicit a tryst with Susanna. The Count’s decision is further solidified by his irritation regarding Cherubino’s behavior, specifically noting that the page had previously been caught hiding in the room of Barbarina, the gardener's daughter. By drafting Cherubino into the military, the Count effectively removes the "amorous butterfly" from the household, forcing him to trade his pursuit of women for the life of a soldier.1