Justify Protestant teaching for me real quick, m'kay?

I just wrote this email to one of my favorite podcasts, one by a Protestant married couple that revolves around marriage and family life. I figured I'd just post it here in case someone wants to respond:

Hello!
I've been listening to your podcasts for several months and I look forward to them every week! I value how conversational it is and how you clearly both make the effort to show love to each other regularly. Additionally, I'm very impressed at how well-organized and researched it is, especially considering your busy lives! Christ's role in marriage has a mouthpiece in your podcast, so thank you!

I was just listening to your latest podcast (on awful marriage advice) and for one of the first times I cringed at something you said. You were sharing how some women in the Nashville mom's group had said that the men needed to "take care" of their sexual needs themselves sometimes. I appreciated that you combated that by pointing out that a man who does so regularly will start to weaken the bond between him and his wife. I want to challenge you to go deeper than that.

Why do you think masturbation is so wrong? I believe it's because it's a lie, just like sex before marriage is a lie, and why artificial contraception is a lie. The sexual act, as you said, was created by God as a part of marriage. It must be free, total, faithful, and fruitful in order to avoid becoming a lie. If any of those elements are removed, it becomes a lie. If a spouse masturbates, he or she is seeking pleasure with the parts of their bodies that God designed to help men and women bond in marriage, grow in their intimacy, be in cahoots with our Lord in creation (if it's the right time of the month) and to communicate, "I give my whole self to you."

Christ's love was and is free, total, faithful and fruitful and He calls us to act that way in everything we do, as well. He withheld nothing on the cross and we are called to do the same for Him and His Church. Marriage is an essential part of that. (I know this is a training video for teachers of this curriculum for teens, but it's a good peek into the Church teaching)

Basically, I'm asking you to justify non-Catholic Christian sexual morality teaching. Hahaha no big deal. I write this with some apprehension because I want you to know how much I appreciate so much of what you share. I also want to *listen* to a non-Catholic Christian try to explain the deep theology.

Thank you!

Elizabeth