I am married and I am now cheating on my spouse with my neighbor.
Why would you want to be with someone who is not your spouse?
I actually do not want to be with anyone else other than my spouse.
You can be attracted to someone without acting on that attraction. You should respect your marriage and end the affair. Continuing to do this will cause you much hurt and regret in the future.
It's nobody's business who I'm sleeping with.
Well if you are cheating on your partner than it is theirs as well. If you do not want to be with your spouse than you are better off getting a divorce before trying to sleep with other people.