Definition: Given a real-life anecdote of a complex ethical situation, generate a suitable title that describes the main event/root cause of the situation. Imagine that the given text is a social media post, and you have to write the title of the post, so the users can decide to read the main text or not.
Input: Ex and I met in undergrad and dated for 3 years before breaking up about 1.5 years ago. We remained friends talking every couple of days (hooked up maybe once a month as well) but it was clear that we were not dating anymore which we made clear to our friends and parents. I met a nice girl through a co-worker and we hit it off after a few weeks and I asked her out. The next day I texted my ex that I was seeing my new gf and that we shouldn't talk anymore and she got upset and demanded to know why when we remained friends long after we had broken up. I told her that I didn't want to put my gf through all the BS associated with SO's still talking to their ex'es and causing unnecessary drama regarding trust issues and whatnot, especially since we were friends with benefits. Ex says that she would obviously stop having sex with me when either of us found a new partner but essentially ghosting the other person is an asshole move. I kind of get where she's coming from because you're not really "friends" if it can end abruptly but at the same time I feel like I've heard of too many situations (admittedly a lot from Reddit itself) where ex'es involved in a new relationship just leads to too many trust issues and insecurities. What do you think?

telling my ex we can't be friends anymore now that I have a new gf