It starts with the most important: Pregnancy prevention. Because if you don't talk about sexual health you can easily create another human by accident.
And it goes on with personal health security. STD is not funny and sometimes it is a fatal issue. Aids is not something you want to talk about. Which means you should prevent others from being forced to talk about it, by talking.
And last: personal sex issues such as the pill leading to a reduced sex drive or similar issues are something that can help to bring health to the relationship.
Ignorance and silence are not effective in preventing sickness, pregnancy, or a healthy sexual psychology.
There is no reason why sex and healthy sex practices shouldn't be openly discussed. Sex is an entirely natural aspect of life. Every living creature reproduces and the vast majority of mammals do it sexually.
To ignore the existence of sexual drivers is to welcome ignorance.