If you think guru ji had sex, u are mistaken. doing even a little naam simran gives you powers, so god himself obviously has the power to do anything, therefore he didnt do it. I heard a kathavachak say that guru ji picked up some seeds and gave them to his wife, thats how she got pregnant. and think about baba buddha ji, how did he bless so many women with children?
kaam means desire, mostly for sex. having sex doesnt mean kaam, kaam is only if you indulge in it, or want more.
guru ji had three or more wives. one was his actuall wife, the others were bhagats in previous lives that did benti to guru ji that they get married to a guru in their next life. So guru ji being god, had to give them their wish.
this is only what i heard in katha. I dont know anything myself. So if im wrong please forgive me.