mrthumbs

Under what circumstances do your nipples get hard?

For example. im aware of the fact that if you are cold they get hard and some other external influences cause that state of nipple.

But now the tricky part:

Example A.
This studly looking juicy type guy gets intimate with you in a romantic setting and gently sucks your nipple.. your nipple gets hard!

Example B.
you fall asleep on the beach on a sunny day while being topless.. you wake up and this nasty old bum is sucking your nipple: does your nipple still get hard?

As in: is this a simple uncontrollable reflex or is there more to it when temperature is not an issue?