Hi there Cameo17,
Welcome to SI. This place helped me so much to navigate the path out of infidelity and its aftermath and I hope it can help you too.
Right now you are framing it as a choice, as your choice, between your wife and your AP. I thought this way too and it took me a good long while to realize that the choice wasn't between BS and AP but between mental health and not mental health. You aren't a safe person to be in relationship right now, not a real and authentic relationship. Both of your relationships are based on lying, hiding and controling information. You say you love your wife, but what you're doing right now is not loving. It's just getting your perceived needs met at other people's expense. Why is it that you're willing and able to do that? That's the question you need to answer. There is a difference between the reasons you felt tempted (lack of sex, money stress, whatever it was) and the reasons you were actually able to go through with it and continue it even now.
hikingout gave you terrific advice. Stop lying to AP. Tell her the truth and end the affair. She'll likely end it for you. Get into therapy and start trying to figure out how and why you have been able to make these choices, and prepare to disclose the truth to your wife. Then buckle up. The reconcilation process is not for the faint of heart.
If you are looking at "what's best" through the lens of "how can I come out of this getting what feels good to me right now (AP) and not come off looking like a terrible person for leaving my pregnant wife", you're most likely going to go on as you are, fucking other people over to get what you want in the moment whether that's feeling good or preserving your self-image, regardless of who you are "with" at any given moment.
It takes so much courage, Cameo17 to drop your defenses, tell the truth, let the chips fall and then begin the heavy lifting of repairing the relationship (if BS is willing to try and you want to try) and rewiring your brain to become a safe partner. It's long and difficult journey, but the work is 1000% worth it.
There's more I could say but for now keep reading and posting. Start educating yourself on the true nature of infidelity and how it impacts the people involved. And get into therapy.
Proceed with conviction and valor. Best to you from this EvolvingSoul.
Me: WS (64)Him: Shards (59)D-day: June 6, 2010Last voluntary AP contact: June 23, 2010NC Letter sent: 3/9/11
We’re going to make it.