Long after the breakup, Cancer Man came back to me.

If you have feelings for him, do it. There is no such thing as "that's it". Don't add such considerations to feelings, it is the purest thing in the world. Don't say anything about reluctance. Reluctance means feeling, and don't say anything about appropriateness. Inappropriate means no feeling. Inappropriate reluctance means inappropriateness, because reluctance is temporary, inappropriateness is eternal, and after a long time, the final result will only be inappropriateness without reluctance.