Nikolita
I think she means that if you're nervous or tense, your body is going to tense up and it's harder for your v****a to be penetrated, whether it be with a finger, p***s, etc.
If you're more aroused and "in the mood", then you're going to be less tense, you will be more lubricated, and so on.
Yes, the relaxation is certainly an issue too. I was talking about the v****a expanding during arousal. So, OP, you could have issues with not being aroused sometimes, or with not being comfortable and relaxed sometimes (maybe being nervous with a new partner or nervous that parents might walk in any minute). Those are things that can make your v****a feel different to him and even to you, as not being relaxed and in the mood can even make sex painful. Here is more information about the v****a expanding during arousal.
"In women who have never given birth, the front wall is about two and a half inches long, while the back wall is about three inches. After birth, it is usually somewhat larger.
However, the v****a is a muscular structure that can expand and contract rather substantially. Normally, the walls are relaxed and collapsed together. But, during sexual arousal, the inner two-thirds expand. This is why the v****a is sometimes called a "virtual space." During intercourse, most women can accommodate almost any size p***s, including a 12-inch one.
A v****a can be either relaxed or aroused. When it is relaxed the walls are collapsed against each other and the cervix lays closer to the front. When it is aroused the cervix pulls up and the v****a walls open apart. This makes the v****a longer and wider.
Whether relaxed or aroused, the v****a walls are very elastic and can stretch enormously in length and in width. The difference is that stretching them while relaxed will cause discomfort or pain whereas stretching them during arousal causes pleasure (up until a certain limit of course!)"
http://kisschanel.com/vsize.html"1. Desire (excitement phase) - Desire is a sexual "charge" that increases interest in and responsiveness to sexual activity. You feel "in the mood." Your heartbeat and breathing quicken, and your skin becomes reddened (flushes).
2. Arousal (plateau phase) - Sexual stimulation--touch, vision, hearing, taste, smell, or imagination--brings about further physical changes. Fluids are secreted within the v****a, moistening the v****a, labia, and vulva. These fluids provide lubrication for intercourse. The v****a expands, and the clitoris enlarges. The nipples become hardened or erect.
3. Orgasm (climax) - At the peak of arousal, the muscles surrounding the v****a contract rhythmically, causing a pleasurable sensation. This is often referred to as the sexual climax.
4. Resolution - The v****a, clitoris, and surrounding areas return to their unaroused states. You feel content, relaxed, possibly sleepy."
http://www.emedicinehealth.com/female_sexual_problems/article_em.htm