choosing friends

ah, the platonic friend. we all have someone that we run to when our hearts are broken or when we're feeling confused. recently my such a friend came to me with her story of a recent breakup; her former boyfriend had left her for another. i consoled her with the standard assurances that the guy must have been a fool for passing up on her. after several evenings of saying how dumb that guy was and how she would have no trouble finding someone else, she told me that it was OK if i wanted to still hang out with the guy and his new girlfriend. "wait a minute," i thought to myself, "why would i want to hang out some random guy--especially her ex?" as it turned out, she was dating an old friend of mine. obviously a friend i hadn't been keeping that well in touch with, but still a long time friend whom i valued my friendship with. (i won't use my usual method of anonymizing with randomly selected letters to represent peoples lest their identities be revealed). now normal breakup protocol states that one should stick with the friend that one was most close with. but what happens if you're equally good friends with both? is it OK to still see both, only separately?