A love bite, or hickey, is a type of bruise. It's formed when someone sucks or bites on the skin hard enough to break blood vessels beneath the skin surface.
When the capillaries, or tiny blood vessels, are damaged due to such pressure, they rupture and the blood seeps out into the surrounding tissue. This results in a red or purple bruise that may change color (to a darker purple, blue, or even black, then yellow or green) over the next few days as the body reabsorbs the blood.
Healing time varies depending on the individual and the severity of the love bite. Usually, it might take a week or two to completely fade away. Applying a cold compress immediately after receiving a hickey may help reduce the amount of blood that leaks out into the surrounding tissue, which can limit the size and severity of the hickey.
Please note, though it might be seen as a mark of passion, it's essential to always get consent before leaving a hickey on someone as not everyone may find it enjoyable or comfortable. It's always crucial to respect your partner's boundaries and preferences in any kind of physical intimacy.