1 From an artistic viewpoint they give a woman very nice curves - as all artists have shown since Roman times.
2 To suckle Children they may have.
3 to give a Woman pleasure as well as a man!
Allowing the child feeding period of a womans life , that leaves a lot of time for pleasurable pursuits so looked at that way - why shouldn't you allow boys to touch and admire them ? I would put it to you that this gives you pleasure also AS WELL as the power this gives you over Boys.