Okay – I haven’t read the responses, just what you’ve written, OP.
Here’s my 2c, as someone whose EX husband wanted to call off the wedding but thought, “We’re already too far in” / “We’ve paid so much for this” / etc. The same arguments you’re using.
This won’t go away. Even if you stop now, even if you cut off your relationship with your BFF entirely (which it doesn’t sound like you intend to – and you need to understand that emotional infidelity is worse than physical in many ways), it won’t make this go away.
You will always know what has happened. You’ll always live with the fact that you’re a cheater, and that you cheated on a man who you love. And you know what? If he’s worth loving, then he deserves better than someone who will sleep around because she’s emotional and has poor impulse control. He deserves honesty. He deserves to know what kind of person he is marrying. He deserves to have a choice in this matter.
You are robbing him of those things.
Marriage takes two people to work. Two people who choose to come into it with all of who they are. It’s not about the fact that you spent $50K on the wedding. This is not about a wedding. This is about marriage.
You wonder how divorce could be more expensive. Give yourself ten years down the road, or twenty or thirty; 10, 20, 30 years of this secret, this hideous lie and betrayal, festering under your skin. It will be just as real that you did this to him 30 years from now as it is today. He will find out. Your BFF might tell him in a jealous rage. You might fall into the pattern of infidelity until you get caught. You might confess after years of guilt. And you know what? You might have kids when it happens. A mortgage. Property together, debt and investments together, a whole life built up together.
And suddenly, all of the trust that he had for you will be gone, because your entire marriage will have been built on a lie. And even if this is the only lie you ever tell him (but it won’t be), he will question EVERYTHING, because suddenly he will see that you were the kind of woman who would betray him and lie to him before the wedding even, and how could he believe anything from that point forward?
Years of broken trust … do you know what it takes to repair that? It’s often not fixable. Attorney fees alone will probably cost more than your wedding, not to mention what he could come after you for in the divorce. In Fault states, adultery entitles a betrayed spouse to quite the settlement.
You are dooming your own marriage with this lie. Weigh carefully whether it is worth it to you.