If you're wondering how to text an ex to inform them you're seeing someone new, the fact is that every breakup is unique, so there's no one-size-fits-all response. There are likely to be various considerations you'll need to examine before deciding to seek out. If you don't want to rekindle your friendship, don't be too flexible. Be nice in the moment, and leave it with a sense of finality. Making it look as though you miss your ex-best friend opens the door to resuming the friendship and/or arguing. You don't have to say things like, "It's lovely to see you," or "See you soon."