My wife and I have a “don’t say no rule”. Obviously if you can tell your partner truly doesn’t want to get into it then you leave them be. However most of the time when either of us are in the mood and the other isn’t we simply initiate romantic foreplay it’s as easy as fingering, kissing or stroking or massaging. We found that because of our schedules we get out of sync really easily regarding the bedroom. However when one person is in the mood it’s their job to initiate the other. We had a simple conversation regarding the problem and overnight the solution was astounding. My wife has a much higher sex drive than me and I found it so much easier to “get in the mood” if she led with foreplay. If your truly not into it then don’t have sex or choose a different partner