'Why is she still going for dinner with her ex?'

My girlfriend and I have been together for six months now, but I get the feeling she isn't over her ex-boyfriend yet. They still chat regularly, and sometimes meet for dinner too. I find this disturbing. She says it's because they're just friends, but what if they decide to get back together? She says she won't, but I'm not sure if she's being honest. Should I forbid her from meeting him?
You want to 'forbid' her from meeting him? Who died and made you king of the world? If she says she's just friends with her ex-boyfriend, why does that bother you? Why shouldn't she be friends with him? And what right do you have to control who she can and can't be friends with, just because you're insecure about your relationship with her? If you don't trust her, tell her about it. If you do trust her, learn to accept what she does and deal with her decisions. There is nothing wrong with being friends with an ex at all. And if she does decide to go back to him, that's her prerogative too.

I tried to end my relationship with my girlfriend by using WhatsApp because I was afraid of telling her face-to-face. Now she says I have to meet her in person and tell her. What should I do? I'm afraid she won't let me end it if I meet her in person, so I am thinking of blocking her on all social media platforms to prevent her from calling me. Is this a good idea?
I think it's possibly the worst idea in the history of bad ideas. What do you mean she won't let you end it? I'm assuming you are both adults. If it's not working, tell her that and move on. And yes, you owe her a meeting. Don't hide behind technology like a coward. That's what supporters of some political parties do in India. Your girlfriend deserves to be told in person.