Final answer:
Alyson and Karin, as a romantic couple who live together, would be considered a cohabiting couple.
Step-by-step explanation:
Alyson and Karin, as a romantic couple who live together, would be considered a cohabiting couple. Cohabiting refers to two individuals who live together and maintain an intimate relationship, usually without being legally married. This term is commonly used to describe couples who are in a committed, romantic partnership and choose to live together in the same household.