During coitus, male and female, kegel each other, there is a different type of sensations which enhances the pleasure of intercourse.
Totally agree with the Kegel exercises. They are very easy to do and you can do them ANYWHERE! Plus it can help with urinary health by strengthening your urinary bladder =)
You can strengthen your muscles by doing Kegle exercises- The aim of Kegel exercises is to improve muscle tone by strengthening the pubococcygeus muscles of the pelvic floor. Kegel is a popular prescribed exercise for pregnant women to prepare the pelvic floor for physiological stresses of the later stages of pregnancy and vaginal childbirth. Kegel exercises are said to be good for treating vaginal prolapse and preventing uterine prolapse in women and for treating prostate pain and swelling resulting from benign prostatic hyperplasia (BPH) and prostatitis in men. Kegel exercises may be beneficial in treating urinary incontinence in both men and women. Kegel exercises may also increase sexual gratification and aid in reducing premature ejaculation. Many actions that are controlled by Kegel muscles include "holding in" urine or avoiding defecation. Reproducing these types of muscle actions can yield stronger Kegel muscles. http://en.wikipedia.org/wiki/Kegel_exercise
You can't. The vagina does loosen over time - there's nothing you can do about it unless you want to pay for vaginal reconstructive surgery - which I wouldn't recommend.