What is rape?

We have seen umpteen incidents of 'Rape' in movies and otherwise. But what is legally termed as 'Rape' might not have caught our attention. There are basically 6 circumstances which are deemed as rape under law.

After having studied the case laws, it is necessary to also study the definition of Rape as given in the Indian Penal Code, 1860. As per Section.375 of IPC a man is said to commit the offence of rape with a woman under the following six circumstances:

1. Sexual intercourse against the victims will,
2. Without the victims consent,
3. With her consent, when her consent has been obtained by putting her or any person that she may be interested in fear of death or hurt,
4. With her consent, when the man knows that he is not her husband,
5. With her consent, when at the time of giving such consent she was intoxicated, or is suffering from unsoundness of mind and does not understand the nature and consequences of that to which she gives consent,
6. With or without her consent when she is under sixteen years of age.

The point which caught my eye and prompted me to post is point number 4. Does it mean a man, cheated by his wife, can file a rape case against his wife's lovemaker? Is not making love with a man of her choice her individual right? Why have not any Bollywood/Kollywood/Tollywood dealing with Behind the wood (read:extra-marital) affairs brought this notion of rape? Why is it always only a man can rape a woman and not vice-versa when the law for sexual harassment is applicable to both sexes (remember Aitraaz)? What about eunuchs?

Disclaimer: I am no way connected to the legal world. My questions may be dumb. I do not subscribe to whatever I have asked ;). I got the above piece of legal information from this source.