we girls don't know but there is something in a girl breast that hurt if u keep holding it hard
they get hard because when the penis enters the vagina the muscles in the breasts tighten.
No. It hurts if you do it too hard, and is rude. But then again, it depends on the girl.
You put your d.ick between them. You squeeze her breasts too hard. Move them up and down your d.ick like you are m.asturbating.
I love girls boobs too much. I want to kiss them and rub these boobs. No boobs didn't grows
Muscles go hard in something called Rigor Mortis, but breasts are mostly fatty tissue so they aren't affected.
Breasts can become firm or swollen due to hormones, arousal, or certain medical conditions, but they don't "get hard" like nipples do. Nipples can become erect or more pronounced with factors like arousal, temperature changes, or stimulation.
No, you have a tumor.
It depends on the temperature you feel; if your going from hot to cold or cold to hot whether its with water or air/wind it could make your boobs hard. Also if you rub your nipple it could make them hard.
Depends what you do with them and how sensitive she is. Some have soft nipples and others hard. Contrary to what many believe, the nipples does not have to be stiff when she is aroused.
I think because of breasts
Although I've never really felt "hard" boobs, I'm assuming softer breasts are nicer to touch. My girlfriend's breasts are soft and supple and I find them very pleasing. Extremely firm breasts seem a bit unnatural to me.