Sex

• https://www.huffingtonpost.com.au/entry/sex-confessions-women-want-sex-more-than-men_n_3203879
• https://www.imom.com/why-husbands-lose-interest-in-sex/
• https://www.psychologytoday.com/us/blog/married-and-still-doing-it/201403/the-4-hidden-reasons-some-men-dont-want-sex
• https://socialnewsdaily.com/71061/men-go-off-sex-quicker-in-relationships/
• https://babe.net/2017/11/09/my-boyfriend-wont-have-sex-relationship-problems-20606
• https://www.tandfonline.com/doi/abs/10.1080/00224499.2018.1437592?journalCode=hjsr20
• https://www.dailymail.co.uk/femail/article-2303648/Why-men-losing-sex-drive-Men-likely-refuse-sex-women--doctors-blame-recession-toxins.html

Men turn down sex as much as women do in long term relationships

https://www.babyboomers.com/article/study-finds-men-turn-down-sex-as-much-as-women-do/5afb2e1ae4b073fac52967b1

This study is arguing men turn down sex with their partner as often as women do. If men are more concerned about the consequences of turning down women in a relationship than the reverse then men probably engage in "service sex" more often than women do.[1] That would imply men's true desire for sex in a long term relationship is actually lower than women's, over the entire population.

[1] I suspect the idea that men are more likely than women to engage in service sex may well be true.