The Front Commissure is the smooth area just above the clitoral head and the clitoral hood or just below where the labia majora meets at the top of the vulva (or genitals).
See the image below.
The front commissure covers the clitoral shaft (a cordlike structure that can be felt… and seen protruding from the skin of the front commissure when the girl or woman is sexually aroused.)

The Front Commissure and The Female Sexual Pleasure
The front commissure is an erogenous zone and plays an important role in female sexual arousal.
It contains sensitive nerve fibers and is extremely and pleasurably sensitive to erotic touch and stimulation during cunnilingus (oral sex).
Particularly, a warm wet tongue on the front commissure feels amazing to women and produces extreme pleasure for women and have them dripping wet in no time.
Girls (or women) who have extremely sensitive clitorises or clitoral heads to the point where direct stimulation feels painful find stimulation of the front commissure during cunnilingus or masturbation equally pleasurable and can orgasm by it.
And there you have it…
…the front commissure.
I hope this article has given you a little insight into the front commissure.