I would describe them as a non-married, but committed couple; she in her late 20s, he in his 30s. They have dabbled in sharing her but are about to embark on a more serious commitment to exploring cuckolding.
Returning to the husband after coupling with someone else presents significant challenges for cuckold couple initiates.
Curiouscpl_k is a slim yet curvy brunette with a devilish smile entirely appropriate for her sassy character.
I believe this is an accurate and concise definition of contemporary cuckolding.