Is your current boyfriend the jealous sort?

If you are in a new relationship, check with your boyfriend if he's cool with the idea of you maintaining contact with your ex: It's important to show that you respect his feelings. You can (and should) reassure your current steady that your friendship is purely platonic and, hopefully, gain his trust.

However, if your friendship with your ex bothers him, then it should bother you too. After all, he deserves your undivided attention. If your boyfriend is the jealous sort, it might be a better idea to let the ex go instead of hanging on and sabotaging your love life.