Sometimes when I hear a person say, “having sex,” I start to wonder what kind of sex?  When I was growing up, "having sex," meant sexual intercourse involving the penis and vagina. Doggy style was considered kinky. Today I find that most of my peers are willing to experiment with different kinds of sex, especially if they are new divorcees or if they just want to spice things up. But, sex has changed since we were kids.  Sometimes when I hear a sexual reference I don't understand, I ask my 22 year old son to explain it. This just goes to show that new sexual practices are constantly being created. However, for the purposes of this quick guide to sex, I'm only going to discuss: intercourse (penis and vagina), oral (mouth on penis), anal  (penis in anus), and masturbation.