Collocations for couple - noun

adorable (AmE), attractive, beautiful, cute (AmE), good-looking, great, handsome, lovely
happy, loving, perfect, romantic
elderly, middle-aged, old, retired, young
heterosexual
gay, homosexual, lesbian, same-sex
engaged, honeymoon, married, newly married, newly-wed
The hotel was full of honeymoon couples.

cohabiting, unmarried
interracial (AmE)
childless, infertile
childless couples seeking to adopt

make
They make a beautiful couple.

the happy couple (= the two people getting married)
We stood and drank a toast to the happy couple.