If you succumb to this temptation, you will bring dishonour on the good name of God and Christ, stumble your husband from faith in God, and prevent this fancy-man (sorry, the man you fancy) from living as a Christian should. You do not mention any children, either. The damage done to them could ruin their lives.
Jesus warned us clearly that even to harbour lustful thoughts for a person we are not married to is to commit adultery with them, in our heart. You seem to have already committed that sin and now you are seeking the approval of strangers to help you proceed to the next stage of actually committing adultery. Please read what Jesus said in Matthew 5:27 to verse 32. Or is Jesus a stranger to you? Are you not prepared to obey Him?
Christians are called to live holy, pure lives. It is a high calling for the One who calls us is High and Holy. Please read all these Bible verses carefully, then you will know not to embark of this course of disaster.
Mat 5:27-28 “You have heard that it was said to those of old, ‘You shall not commit adultery.’ But I say to you that whoever looks at a woman to lust for her has already committed adultery with her in his heart.”
1 Peter 3:15-18 - It's God's will that your honourable lives should silence ignorant people... and,
verse 24 - Jesus carried our sins, so be dead to sin
1 Peter 4:16-18 - be done with sin, no longer plunge into sin as worldly people do; they heap abuse on you for being different. But if you're not different, you cannot point them to Christ! And,
verses 14-16 - there's no shame if you suffer for being a Christian who is different to the world.
2 Peter 3:14 - Christians must live peaceful and blameless lives.
Romans 6:1-7 - We must not keep on sinning.
Romans 8:4-9 – The sinful mind cannot submit to God’s law but those indwelt with the Holy Spirit do.
Romans 12:1-2 - our bodies are to be living, holy sacrifices to God.
Galatians 5:16-26 – former conduct compared with the fruit of the Spirit.
1 Corinthians 6:9-11 - consider who won't inherit the Kingdom of God...
Ephesians 4:22-32 – the new self, protecting it from deceitful desires, not grieving the Holy Spirit.
Philippians 1:10; 2:15 & 4:8 - how our thinking is to be purified.
1 Thessalonians 4:3-8 - Be holy, avoid all sexual sin.
Colossians 3:5-9 - Put to death sinful earthly desires.
2 Timothy 2:19-22 - Turn from evil, flee youthful desires.
Hebrews 12:10-15 God's discipline is always good for us, so that we might share in his holiness… work at living in peace with everyone, and work at living a holy life, for those who are not holy will not see the Lord.
Jude vs 4 – godless men, who change the grace of our God into a license for immorality and deny Jesus
Revelation 21:8 - Outside the Kingdom are greedy immoral liars etc.
1 Peter 3:15:9-11- Do not insult, but bless, do not speak evil or deceit.
Ephesians 5:3-4 – No impurity or obscene/foolish talk for God’s holy people.
James 1:19-22: "Everyone should be quick to listen, slow to speak and slow to become angry, for man's anger does not bring about the righteous life that God desires. Therefore, get rid of all moral filth and the evil that is so prevalent, and humbly accept the word planted in you, which can save you. Do not merely listen to the word, and so deceive yourselves. Do what it says."
Yes, it's impossible to be sinless, but we should sin less. The more you contemplate the horror of all our sin being dumped on Christ, on the cross, so that the sinless Jesus became sin, the easier it will be for those indwelt with the Holy Spirit to change with regard to how they view sin.