Is it ever okay to forgive a cheater?

I have had a couple of bad experiences with some past girlfriends and since then i tend to be very strict with the way i handle my relationships i do not believe that a cheater deserves to be forgiven, i think cheating itself is simply an act of selfishness and disrespect and those who do it are not worthy of second chances whoever i often wonder if that's always the case, experience has taught me that cheaters don't change but i have been in situations where i had to put some consideration before making my decision, thus i wonder is it ever okay to forgive a cheater?