My girlfriend's ex-boyfriend is always harassing her.

First of all, you need to talk to your girlfriend, and you must reach an agreement. You don't have to ask her not to do those things, but learn to tolerate some things. Because loving a person not only loves her advantages, but also loves her shortcomings. Besides, your girlfriend is not a shortcoming, just too kind or vain. Do not give up the attention of the opposite sex. So, you must tell her your troubles and your concerns. If your girlfriend really loves you, you must pay attention to it.

Secondly, you can talk to her ex-boyfriend, explain your unhappiness and warn him not to think too much, otherwise you're welcome.

Finally, you have to understand that love is sometimes not a simple thing, and there are many twists and turns in the middle. Only when two people are sincere, frank and care about each other can they go smoothly and be happy.