From the beginning of time there has always been someone motivated to disguise sin-dress it up-make it more palatable. What are drunken frat parties about; why do people perpetrate identity theft; what's the deal with drug dealing? Call it all what it is-purely selfish disregard for anyone else-if it feels good do it mentality-pleasure seeking without boundaries-SIN.
Don't get it twisted. If you are on the verge remember "Sin will take you farther than you want to go, keep you longer than you want to stay, and cost you more than you want to pay." Not sure what motivated the question but its never too late to change your mind. If you need to hit rewind do so immediately-you'll be doing both parties a big favor. Stop and make the next right decision-do the next right thing. You can repent and be forgiven-its never too late.
If you are the victim of a cheating spouse, don't ignore it. You're not a doormat. Be direct and insist on your right to be respected and treated honestly. Stay as composed as possible. Don't beg and don't loose control. Seek wise council and take it day by day.
God has assistance and guidance no matter what side of this coin one finds themselves on-its called Godly grace & mercy.