Originally Posted by By your Command
I'm hoping the humour comes from Wolverine, I miss funny movie Wolvie as opposed to deeply in touch with his feelings/angry Wolvie, cause Bobby being funny out of thin air for the fourth movie would kinda be weird, probably a perfectly explainable coping/defense mechanism for the apocalypse, but nonetheless weird.
Iceman has had a glint in his eye before and shown a cute, mischievous side, turning Pyro's fire-globe into ice that smashed on the floor in X1, and freezing Wolverine's hand when Logan arrives back at the mansion at the start of X2. Also, taking Kitty to skate on the pond in X3 as a way of lightening the mood.
He's not some gloom-ridden misery-guts; he's clearly done light-hearted or cheeky things before.