Yes.
yes
Male nipples have similar nerve endings to female nipples, making them sensitive to touch and stimulation. This sensitivity can vary among individuals, with some men experiencing heightened erotic feelings when their nipples are touched due to the release of oxytocin and endorphins, which are associated with pleasure and arousal.
Presumably they enter into the spirit of what they are doing and stay in a state of arousal.
it's called arousal. google it.
Its a very sensitive part if the breast. It has a lot of nerves in it & it stimulates arousal.
Upright.
No in some cases but if the girls a kinky minx she may enjoy it because it will make her nipples erect and easier to 'play with' which is perfect for arousal.
When men get excited they have erection(penis) similerly girl have nipples tighten.
The breasts and especially the areola and nipple of females can be very sensitive and give pleasure during arousal and coitus.
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.
Erect and hard nipples, body heating up, heavy breathing, vaginal lubrication/wetness and fast heart beat.
It turns most girls on and makes them horny. Not all girls find it as a turn on though, it depends on the girl. you don't actually suck on the breast, you stimulate her nipples.