Do the girls' nipples erect always when aroused?

It absolutely does not make a difference. I must say I'm one of those lucky girls whose nipples never seem to erect no matter how aroused or turned on they are. sometimes it makes me self conscious around my guy because he thought it was like a penis erection type of thing, but I told him what I'm telling you and now its all good. haha but honestly its no indication of how much a girl is turned on. Some nipples are just more responsive to touch while others respond more to temperature (similar to what gravygirl said). So if you are getting intimate but there is no "nipple erection" don't fret. Look for other indications that she is enjoying herself.chances are she is.

Mine seem to respond a lot more to temperature than arousal. I mean it feels good if they are played with, but they won't necessarily stand at attention. It's not the same as a penis or something. And sorry, but I don't know anything about inverted nipples.

mine usually do but I wouldn't go by that. I'm sure not every girls' does every time

some nipples don't respond to touch and aren't sensitive that way. I would not use that as an indicator or rather she is aroused or not.

girls nipples are hard when its cold too. I know when I'm really horny and aroused, (and its hot) my nipples are hard. ;-)

not always.