Yes I did.did you masturbate?
Your question itself has an answer. If you feel that what you did is not wrong, then you wouldn't question whether its a relapse or not.
It is a relapse unfortunately.
I would say that masturbating to phone sex is imagination or fantasy or whatever. Actually, watching porn has visual stimulus but erotic literature or phone sex have no visual stimulus. So, phone sex/erotic literature are definitely considered a relapse.