While sex is so common in our society, not to mention so essential to human survival, it's no wonder that we dream about sex. Like any dream symbols, what sexual intercourse means to you in a dream will depend on your feelings about it and your experience as a sexual being.
Interpretation of sexual dreams.
In some cases, dreaming about sex does not always mean sex. From a psychological perspective, dreaming about having sex symbolizes the integration of contradictory perspectives on yourself or the need to combine the perspectives of your dream about your sex partner with yourself.
Sex partners in dreams.
Dreaming of having sex with someone other than a husband or partner, or with an imaginary lover, may be the fulfillment of a wish.
Alternately, if you keep thinking about sex or having sex in real life, it may be a continuation of your waking thoughts and actions.
Sleeping with your ex may be a sign that you are receptive and ready to the idea of ending the relationship, or that you have learned from your previous experience and are thinking about what you have learned. Your ex may also be starting a new relationship, it may be a warning that you don't want to repeat previous mistakes. If you still love your ex, then dreaming about having sex with your ex can be a wish fulfillment.
Interpretation of watching pornography.
If you watch other people have sex, or watch porn, you may feel insecure about your sexuality. Watching others may be a way for you to learn about different sexual acts and/or discover your own sexual needs and desires. It may also be a need for feelings of love or a desire to be loved and desired.