That’s my story and I’m sticking to it.
Unless a romance author is aiming for a particular publishing house, keeping the heat and the duration of the sex scenes adjustable is advisable.
Write what you feel is “right” for your story. Don’t push up the volume or tamp down on the sizzle in your first version of the manuscript. Send out what you believe is the best version of your story. If a publishing house feels the novel has marketable merit but only needs a little heat control, they will tell you. At that point, ride the sex dial in whichever direction you must.
Until then, trust your gut.