Accidently creating new alters via role-playing OCs?

My 2 most recent new alters are fictives that seem to have been created because of OCs I roleplay as.

One of my OCs is Harvey Bullock’s son. I have been role-playing as this OC for over a year without an issue. Then I had Harvey Bullock show up co-con one day saying he heard he had a son here and he seemed like he wanted to meet his son. That was the first time I saw/met this alter, so I’m pretty sure he was brand new to the system. I had to awkwardly be like, “I’m sorry, he doesn’t actually exist, he's just someone I made up and roleplay as… Your son isn’t here…”

Has anyone else had an experience like this? How do you handle it?

Should I give up roleplaying, so I don’t accidently trigger the creation of more fictives I might let down? Roleplaying is one of my favorite hobbies right now and has been helping me cope with life, so it would suck if I had to stop, but I might have to, right?