sexpanion
A person you are fucking, BUT are not in a relationship with, yet they are more important than a fuck buddy.
Have you seen your sexpanion this week, your skin is glowing? (That would be referring to your sexpanion orgasm)
Or...what did you do Saturday night? My sexpanion! Duh!!
Or...what did you do Saturday night? My sexpanion! Duh!!