You see your attractive neighbor and know how much sexual desire you have, but you decide not to do anything about it since both of you are married and you respect this holy institution.
This might be the right choice, it might not be. Only you know what is right for you and you have to make decisions like these every day. By making them and by experiencing how your world reacts you fine-tune yourself along your spiritual path. If you try to repress your desires by saying "I must not look at my attractive neighbor" or "I only must have holy thoughts", your repressed desires will come back in one form or another to haunt you.
The Gita describes God as the absence of desires: once you stand still, without any desire to move, you will see Me. But I fear the Gita has been written for God-like humans. Arjun looks like a little child next to Lord Krishna with his whining questions and endless repetition of concerns. What you probably don't know about him is that he happens to be the 'best of the best' of us. He once was in a shooting competition with India's best archers and he won with a perfect track record. When his teacher asked him to share his secret he said "When I aim for the bird on the tree, I aim directly for the eye and I do not shoot before I have perfectly zoomed into my target."
Do not beat yourself up over who you think you are right now. You may have to question some of your desires just because they may be distorted outlets of different urges, but once you have disentangled them, go after your desires with laser-loke focus. With every desire you have there is a perfect opportunity to express yourself beautifully today without being in conflict with who you really are. Desires do burn off as you get what you aspire. 'Been there, done that' happens to be a holy mantra in my opinion.