Today’s idiom: wear your heart on your sleeve
Meaning: not hiding your emotions, openly displaying them
Origin: There are three theories I found regarding the origin of this phrase. 1. During the middle ages when jousting was still a thing, knights would tie the colors of the lady they were supporting on their arm. 2. Also during the middle ages Emperor Claudius II didn’t allow marriage because he thought that unmarried men made better soldiers. As a compromise, he allowed temporary coupling, where during the festival of Juno men would draw a name of a woman and wear her name on his sleeve for the rest of the festival and for the rest of the year they would be a couple. 3. Shakespeare wrote it first in Othello.