I get the premise of the argument and at some level I agree. But equally, if put into that position of being cheated on, I would want to know, especially if the person decides to take option number one and reconnect to how much they love me. I imagine it would be immensely painful but, by not telling them, you’re robbing the other person of agency in the relationship. Maybe they’re not okay with being cheated on and want to leave? Maybe they’ll accept your apology and stay? Either way, the choice is theirs.