The penis IS a sex organ, a genital. It is also for urination, so it is multi-functional.
The breast is no more sexual than any other part of the body. It does not have a secondary purpose. It is not multi-functional.
Using a breast in sex play is no different from using a foot or a neck. If you want to say that your whole body is "sexual," that's fine, but that doesn't mean the human body is composed entirely of genitalia.
ETA: This whole site is great: http://www.007b.com/
The breast is no more sexual than any other part of the body. It does not have a secondary purpose. It is not multi-functional.
Using a breast in sex play is no different from using a foot or a neck. If you want to say that your whole body is "sexual," that's fine, but that doesn't mean the human body is composed entirely of genitalia.
ETA: This whole site is great: http://www.007b.com/












But that's a whole NOTHER can o' worms.
