Do you think sex is the ultimate way of expressing love?

Do you think sex is the ultimate way of expressing love? I'm not saying sex is the only way to express love nor that having sex necessarily means you're expressing love- clearly it doesn't if you just have casual sex for example. But in a loving marriage or relationship do you think having sex is crucial? Obviously some couples can't have sex due to medical reasons and other things but in general do you think sex is a necessary component of a relationship?