If you mention another girl’s name to your girl, she’s never gonna forget that name. She might even look her up online to see what she looks like or see how you guys talk online. She’ll compare herself to that girl & see who’s prettier. It might even bother her that you guys talk a lot and she might assume there’s something else going on. If she starts bringing her name up and start saying things like “Why don’t you go talk to ______, maybe she can make you happy”, she’s either a bit jealous, or she just doesn’t straight up like the bitch.