My colleague (male) and I have been on good terms/ friendly for the past few years. He started to get a bit flirty over text and I foolishly didn't rebuff him, but I wasn't flirty back. However, it's starting to get too much now. He keeps messaging me in the morning saying "hi beautiful." And when I don't message back he sends loads of messages asking if I'm okay and what's wrong.
He's about 7 years older than me (and much higher up in the company) and I have to communicate with him for work purposes so I can't block him. He's also married.
He could make things difficult for me if he wanted to which is why I haven't explicitly told him to stop, but I have been ignoring the inappropriate messages and only replying to work stuff. So maybe I'm partially to blame, but I hate that I've got myself into this situation and now I'm not sure what to do.
He's tried to call me numerous times at 7/8pm at night. I never answer.
I'm not sure what to do.