When your ex starts dating, be mature about it. The two of you didn’t work out for a reason and you’ll see that in time. Don’t be rude when they start dating and the phrase “sloppy seconds” needs to fade out because 98% of us could be considered “sloppy seconds” if we’re not the first person our S.O. has dated. Just let them move on with their lives and you do the same. You can’t move forward if you’re still hung up on the past.