These terms refer to lovers or love-making. Each has a sexual connotation and may be considered less chaste than loving when used as an adjective. An amatory or amorous look is stronger (more sexual) than a loving glance. There is little distinction in meaning and usage between amatory and amorous, although the latter is more often applied to persons than is the former (an amatory letter; an amorous relationship between Hal and Judy).
Dictionary of problem words and expressions. Harry Shaw. 1975.