This is a question for women (and also for men who wish to recount the experiences they had with women; but this is not about male preferences):
Do you need artificial lubricant for comfortable penis-in-vagina (or dildo-in-vagina) sex? Has it always been like that, or has it changed along time? (Obviously menopause may have changed the situation, for instance.) Is it always the same along your menstrual cycle? Is it different when using a condom?
(Own experience: my wife does not need it, but at the very beginning we used lubricant because she was not yet used to sex with me, and also we've used some for sex during periods after removing a tampon, as the tampon dries the vagina. I think also for sex with a condom.)