Red asked a bunch of questions. This post was only after I didn't answer a much more detailed email from her two days before. It wasn't that was avoiding the questions it was that I was really busy with some other stuff. I woke up at 3:40 this morning and couldn't go back to sleep so I decided now was as good a time as any. So here are Dr. Joe's answers to the publicly available version:
Q: What is sex? Is it the act of intercourse carried to its fullest extent of a man orgasming inside a woman?
A: Technically speaking that should be "ejaculating inside a woman" the orgasm doesn't really happen inside the woman. But nit-picking aside, in this context it's called sex if it's a sexually motivated phenomena or behavior. Hence "phone sex" is still sex even if you are using it as a communication device and not as a toy.
Q: Does the man pulling out right before he orgasms count as sex?
A: Yes.
Q: Does a man entering a woman once count as sex?
A: Yes. Ask a rape victim. Or imagine what one of your parents would say if their spouse used that argument as a defense against infidelity.
Q: Is any penetration of the vagina sex?
A: No. There has to be sexual motivation. Hence the exam at the doctors office probably isn't sex even though there is penetration.
Q: Then that brings up hand jobs. Is that sex?
A: Yes.
Q: Does cyber sex count as sex? Does phone sex count as sex?
A: Yes and yes. It's called sex isn't it?
Q: Does thinking about sex with a man count as sex?
A: Now you have asked a more interesting question! No. This is actually more of the motivation for the phenomena or behavior, not the phenomena or behavior.
Q: Where is the line of virginity drawn these days?
A: It probably has always had a little bit of fuzzy definition. But probably the clearest line can be draw with sexual intercourse. Once the male has penetrated the woman's vagina with his penis, even a small amount, they are no longer virgins.
Q: What is cheating?
A: That is going to depend on the rules of the relationship. For some couples having lunch with a member of the appropriate sex with the intention of pursuing a sexual relationship is cheating. For other couples having complete intercourse with everyone at the orgy is not cheating. It's about breaking rules, not the acts themselves. Those rules are defined by the people involved. Problems can arise when different parties to the relationship are working from different understandings of what the rules are.
The rest of the questions, while important relationship questions, are beyond the scope of Dr. Joe's expertise (sex). The two things I will tell you are that: 1) you are 21 years old and at that age it is normal to be asking those type of questions; and 2) For the most part you will have to answer them yourself.