Are you lusting? Are you wanting to perform the sexual act? If its the right person? You might feel that way also... But, love of a mature believer will refrain you. But, if its a person whom God would not have you to marry? You are on your own making up your own mind.
God sees our thoughts as actions. For when God thinks something, it happens. He is now training us for our eternal life. What we think is the issue. Not simply our overt actions. We must learn self discipline.
Some people self righteously think they do not sin because they never act upon their thoughts and desires. That was the sin of the Pharisees.
We are all sinners. We are to learn God's Word in depth so we can learn to relax in God's presence and not to condemn ourselves. When a believer gets to that place it really burns the devil who takes please in the power he feels in making a believer feel bad in guilt feelings.
That does not means we are free to sin. It means we must learn how to be free to serve God even though we can still sin. God knows we are still weak in our flesh. That is why He gives grace to the humble believer who has no illusions about themself.
But he said to me, “My grace is sufficient for you, for my power is made
perfect in weakness.” Therefore I will boast all the more gladly in my helplessnesses/weaknesses, so that Christ’s power may rest on me." 2 Cor 12:9
While Paul was feeling his weaknesses, yet he boasted (befor all the accusing angels to hear) that God's grace was keeping him and enabling him... and even energizing him, to face them with righteous defiance!
Keep always in mind...
"Therefore, there is now no condemnation for those who are in Christ Jesus."
Rom 8:1
Those verses are for us to learn to live by..
And, live IN, as our castle. Our shelter in the Devil's world we now find ourselves in.
grace and peace!