Robyn, Dylan was pretty grumpy about the new babies, too. But then, he really does not like being handled too much anyway. Maybe Tigger is having a combination of both things?? I would not worry too much. Maybe just pet him gently when he comes to you and don't push yourself on him until he is ready for it - that is how Dylan wanted things, anyway.
Is Tigger grumpy about his belly anyway? I know Dylan sure is!!! It is only ok if he rolls over and invites a schmoozle - otherwise HANDS OFF