As far as I remember, they did not come to town together.
They did hook up in the past when he was a struggling artist and she was involved in the art galleries or something along those lines.
Ava got pregnant and Franco believed Kiki to be his daughter. When Ava saw Franco's dark side, she tried to keep Kiki away from him.
Of course later it was revealed that Kiki is actually Dr. Clay's daughter. Kinda too bad because I liked the chemistry with Kiki (Starr) and Franco (Todd).