Question: I have a couple questions for which I have been unable to find answers either in books or on the internet. Here they are: (1) I understand that a male's penis throbs or pulsates when ejaculating his semen. During sex [intercourse], can I feel that throbbing? Will I feel his semen spurting into me?

What happens to his semen after it is deposited in  me? I know that the sperm cells swim farther up, but what happens to the semen? Is it absorbed, or does it flow out like menstrual fluid?

Answer: It is unlikely you will be able to feel him ejaculate or the throbbing of his penis, as the inner vagina is usually sensitive to only pressure, not touch and friction. Consider how faint your pulse is in your wrist, now imagine trying to feel that inside your vagina. If you hold his penis in your hand while he ejaculates, you will be able to feel the amount of stimulation the vagina will be exposed to, while noticeable with your bare hand, it is not significant. If the penis is being moved in and out, it will be even more difficult to be aware of small changes in the penis.

Some of the fluid ejaculated flows back out of the vagina, as a result of gravity; it is mixture of your own body fluids and his. See the link below for a woman's experience of this.

http://myvag.net/flowback.shtml