I pride myself on knowing a lot about sex

My sister and I were talking the other night and she asked me if I had ever heard about a woman having a "tickler". I told her I had not and asked what she was referring to. She told me that her husband had told her that there is a spot in her, that when he hits it, it tickles his head and makes him ejaculate immediately. I have been looking for the answer to this and have found nothing, but my guess is that it is her cervix. Can you please tell me what you think? I pride myself on knowing a lot about sex and I am always wanting to learn more.

I’ve never heard about a "tickler" before either. But I think you’re probably right about it being the cervix and the area just behind where the cervix enters the vagina. Barbara Keesling, in her book Super Sexual Orgasm calls this spot the "cul de sac". There’s also references to the power of this spot in the ancient Arabian love manual The Perfumed Garden.

When a woman is very aroused her vagina expands and lengthens. If she has a certain amount of control over her vaginal muscles she can push down, exposing this special spot to the head of her man’s penis. It brings great pleasure to both partners.