It really depends on the nature of your relationship. If you have established exclusivity, then certain boundaries will need to be respected or at least discussed. There’s nothing wrong with a harmless flirt/chat at a bar – your man needs to be secure and trusting enough to deal with it. After all, he’s probably doing it, too. Exchanging of numbers is slightly dodgier territory as it is an invitation to carry on or extend the dynamic. Sure, this could be purely platonic, but more often, it isn’t.