It's not so much a "timing issue" as much as it is how comfortable two people feel with one another.
Most couples start off flirting with one another or using sexual innuendo playfully before seriously discussing the possibility of having sex. Other couples simply go with the flow. Meaning if it "feels right" in the moment they'll allow physical chemistry to take over following a series of passionate kisses....etc
Life is a personal journey.
Each of us gets to live it on OUR own terms.
When it comes to relationships there is no "right" or "wrong" per se but rather "agree" or "disagree"
Ultimately we're all looking for someone who wants what we want!