Although Marion Wormer, in Animal House, famously says “vegetables are sensual, people are sensuous,” she is wrong. Sensuous, a neutral word, means relating to or involving the senses; sensual means relating to pleasure or the physical (especially sexual) senses. A person’s excitement can be more sensuous than intellectual, but that does not make the person sensuous. And vegetables may fulfill sensual pleasure but tend not to be sensual themselves.
I encourage adhering to the two terms’ strict senses, though I must acknowledge that sensuous is increasingly being mistaken for sensual and may someday lose its distinct definition altogether. If such development ever becomes standard, sensuous should be abandoned for the more accurate and visceral sensual, and sensory, the most technical of the three words, should be used when meaning relating to the physical senses.