It's from Star Trek: Deep Space Nine. The two characters belong to a race of nearly immortal worm-like symbionts who are transfered into human-like bodies when their previous host dies. They were in a heterosexual marriage when the prior male host of Jadzia Dax died.
Isn't Rosha/Jolinar and Martouf/Lantash about all you'd get? Apophis and Amunet (Sha're) & Baal and Qetesh (Vala) in Continuum are the only ones I can think of where we ever see a Goa'uld couple, but we don't see them smoochin'
