husband’s sex drive

My husband always has a higher libido than I do but it’s exponentially more when I’m pregnant. Apparently “I’m so hot” lol. While I love that he wants me we’ve been bickering about how much sex we need to be having. I’m 22 weeks pregnant and still breastfeeding my 14 month old and mommy is tired and touched the F out most days. We’ve been having sex about 1x a week which is about all I’m interested in but he’s not happy. Does anyone have any good articles, resources etc that I can share with him about hormones, touched out . . Thanks for your help!