What is the adjective of couple?

The Word "couple" is a noun, usually referring to two of something (I will see you in a couple of days); but it can also refer to two people in a romantic relationship: When Joseph and Anne began dating, their friends wondered if soon they would become a couple. You can use any appropriate adjective that describes the two things or people. For example, My mother and father remained a loving couple for the 45 years of their marriage. (The Word "loving" describes couple.)