There is Christian material on this subject, but it's awfully hard to come by. (No puns intended).
Of course there is the Biblical discussion in 1 Cornithians 7. Genesis 2:24 even sums up the physical act as a DEFINING part of marriage. And there is Proverbs 5:18 and the following verses, which state a husband is to be satisfied with the wife of his youth for all of his life - but what gets overlooked is that that also implies an obligation on the part of the wife to help provide that satisfaction.
The Christian literary / relationship advice world is extremely biased against the husband on the point of sex, and there's just no way of getting around it or denying it. The eptiome of this anti-sex bias is this book:
This book consists of a writing/devotional for every day of the year. 365 of them.
364 of the pages are about the "relationship" sort of things that a good husband needs to do for his wife. You know, the kind of advice that we get anywhere and everywhere else. And I don't mean to dismiss this. Yes, I know it's important and yes a husband has the obligation to do all those things (anybody who's read a book on relationships or romance knows what they are because he's read them ad infinitum, yada, yada, yada - you know what I'm talking about too).
Like I said, 364 pages telling husbands how to behave themselves and what's required of them in a Christian marriage.
All except one. March 15. The ONE page that says boo in the way of acknowledging that - oh yeah - it might be a good idea if the wife could be so kind as to taking time out of her busy life to make a point of putting out for her poor husband once in a while.
I know that sounds as bad as some of the posts of YOURS that the women here get up in arms about. But a Christian man - especially a HUMAN Christian man and CERTAINLY a human Christian man who happens to have been cursed with a sexless marriage - would understandably be just a little testy after having read material such as this.
This is probably the next best book to Dr. Laura's Care and Feeding of Husbands, which itself isn't a "Christian" book. But I doubt you'll find a Christian book that comes any closer, because this guy lays it right on the line and identifies "sexual fulfillment" as being at the TOP of the list of things that a husband can't live without.
Don't bother showing it to a wife, though, because even that book is still stacked 90-t0-10 percent with the list of things the husband has to do to keep his wife happy. Which of course a husband is perfectly happy to do if he's getting what he needs, but when he's sex starved, sorry, but he's really no longer in a mood to read, let alone do, it. And that unfortunately is the point to which I've gotten.
Bah. I just get into moods at times and this is one of those times. And then I read my "Christian" New Man magazine which features regular articles by Dr. Douglas Weiss. He's a Christian "sex authority" - NOT. To steal a quote from an Everybody Loves Raymond rerun I just watched tonight, he "should have his male organ revoked." He's not a real man. He can't possibly be. To read his articles, you'd believe we not only should not masturbate, but we should be grateful for what little we ever do get, and accept as a given that we're obligated to accept far less sex than we want because we're not entitled to it. Oh, yeah, if and when I get into moods like this it's very likely to be shortly after I've read some of that "so-called Christian" anti-husband CRAP.
Oh well. Romans 8:28. God takes everything bad and works it for good. Somehow. Eventually.
