What should I do if my boyfriend still answers her text messages despite knowing that he still likes his ex-girlfriend?

As a boy, I answer your question. In fact, you should feel very lucky. This shows that he is very caring and responsible. If he can do that to his ex-girlfriend, then how do you think he will treat you? Well, the answer is self-evident! I really congratulate you. Now, as long as he understands the relationship between them, dating is okay. Boys prefer girls who are open-minded. I can understand your feeling, but if you want to understand, it is better to block it. If you don't ask him to date, he will secretly reply to text messages, which will make you feel even more uncomfortable. If you ask him to date, he will still feel guilty and treat you better. I wish you happiness!