The bible clearly states that fornicators will not inherit God's Kingdom, but the question is "what is a fornicator"?
If I remember correctly the word fornication is derived from the greek word "porneia". The problem is there are different defintions of that word porneia. Some say that porneia would include any type of sexual activity outside of the marital arrangement and certain types of sexual activity within in the marital bond. (masturbation, sodomy, adultrey, bestiality, homosexuality, incest) However others say that porneia refers to sexual practices that are extreme, bizarre or harmful. The only way to know for sure is to closely examine the Greek terminology as it was used during that time.
Another interesting view about sex in the bible is that incest and adultrey are mentioned without any negative views. For example Abraham and other bibical figures were known to have sexual relations with their concubines despite the fact that they already had wives. It is said this was done so that the nation of Israel could multiply their numbers quickly, but this practice was continued even after the nation of Israel had numbered into the millions.
Then there is the issue of certain incestual relationships. Sarah was Abraham's half sister but yet they were married and even had offspring together. If I remember correctly Noahs daughters intoxicated him and then had relations with him, of course this was said to have occured so that their line would continue.
Another interesting aspect about sex in the bible is that angels at one point had materialized into fleshly bodies on earth so that they could have relations with the daughters of men. I find that account to be amazing, imagine an angel being so infatuated over a human female that they would leave heaven to pursue a physical relationship. If powerful and perfect angels can be tempted like that imagine what the lowly imperfect man must be going through.
Kinda interesting when you think about it