TTC from the male's point of view...

Anyone found any websites/articles/books I can give to my husband to read? He seems to think having sex whenever will be successful & couldn't understand why I refused to give him 'extra lube' with my mouth. 
We both work long hours & it's up to me to get things going when it's the fertile window which is hard when I'm tired also.  I try to put on a brave face but it's so painful when he's not interested as I feel like yet another opportunity is just passing us by.
Thank you for reading.