I think he wants to date me (long story)

Liz
A week before I left college an old "friend" of mine's texted me, asking to hang. Our past is that I couldn't stand him with a passion our freshman year. 10th grade, I started dating a guy when I stated talk to, lets call him, Bob. Bob was going through somethings and so was I. We talked until he begin flirting with me, wanting more than friends, but I was in relationship. After my bf and I broke up, Bob trird again but I said I wasn't ready. A year or two later leading to 12th grade, I begin dating someone else and he was angry. He went and told my sister secrets I told him. I was upset that he did, but he doesn't know my sister went back and told me. He is now back texting everyday, but I don't know his why. Would you be okay talking to someone who done this?