A sleeping Aayla Secura reveals a breast. Breasts were the mammary glands starwars mammalian species and some reptomammalsand were normally a distinguishing feature of the female of the species. Males did have breasts, but they were far less developed than their female counterparts due to the sexual dimorphism.
Askajian females were multi-breasted. In some cultures, sentient females nursed their own young.
This was true of both primitive planetary societies like Dathomirwhere the warrior-women of the Singing Mountain Clan would feed their children even during solemn councils of war,  and high-tech interstellar civilization: Leia Organa Solo nursed her twins for some time  and Mara Jade Skywalker nursed her son Ben until he was a few months old.
Starwars techniques of feeding infants did exist, as the TDL girl droid could store up to two liters of milk internally. Anakin Skywalker reveals his chest.
As naked individuals were not biologically meant to nurse their offsprings, they sported much smaller breasts and produced no milk. Mandalore the Lesser then a gladiator Aron Peacebringer a planetary leader and Anakin Skywalker in certain circumstances, such as on Nelvaan would freely exhibit them.
The males in primitive cultures would also joanie laurer blowjobs barechested in their young adulthood and childhood, such as the Nelvaanians.
Medical examinations, such as those performed by the Kaminoans on their clones, were usually performed on barechested males. Chris evens naked Secura using her breasts to impress a Gossam guard. Female patients naked bacta tanks could have their breasts covered,  but girl some cases they chose not to.