Some believe masturbation is sexual immorality, others don't. Some believe all sexual acts other than man/woman missionary position are immoral, others not. Some believe all homosexual relationships are sexually immoral, others don't. Some believe homosexual relationships within marriage are not sexually immoral. Some believe homosexual relationships within committed relationships are not immoral. etc.

Obviously, there isn't agreement on what sexual immorality is and the bible is not clear on the issue. Thus it is a disputable matter.