The first lie. Period. I believe firmly if you tell that first one, it has to "snowball" and you must cover one with another, and another.......Nope. Not for me. I have always prided myself in being honest, even if it get's me into trouble, and believe me, it has.
When they cheat, Lie & Know there not telling the truth! A relationship is built on trust and opening up to that one person you know you can always go to nobody what the situation is . you should be able to tell them the bads and the goods . Even if you know what there going to say . Just letting them know whats on your mind will show them you trust them and You don't want to hide anything from them and it even builds even more trust for them so Be honest and faithful mostly! And your relationship will work out :)
In any relationship, when you are the only person trying to keep the relationship going that is a red flag. Enough is enough when your efforts to keep the relationship are the only efforts to keep it going. There are plenty of people on the earth that can be in a good relationship with you, if you start looking for one. Don't settle for some ingrate, who cares nothing about you. Find a more serious person to have fun with. Be happy.