My boyfriend proposed to me, but he still keeps in touch with his ex-girlfriend.

You should know that men's psychology is very complicated.

How to say it is a bit mean, what you can't get is always the best.

I like him, miss you during the day and beg my ex-girlfriend to come back at night.

First, he may not want to get that woman back before marrying you, and then let that woman see you get married and shake it well.

Second, he couldn't accept the fact that he was dumped by his ex-girlfriend and kept fantasizing about her coming back. And you, comfort him when he is empty, so that he can't let you go, so he wants to be with you before his ex-girlfriend comes back. If his ex-girlfriend really doesn't want to look back, he will marry you if you get married, or he will kick you.

To put it simply: He wants you to be a spare tire with no regrets.