Originally posted by StiltmanFTWIn the director's cut it's revealed that it's actually Bill's cock wearing a glove that is holding the hammer.
"I will take your arm with it".I assume Thor meant he could summon Mjolnir so fast, Bill's whole arm would get torn off in the process.
Bill is a Korbinite Cyborg though, not a human, so even such a gruesome wound *shouldn't* be lethal to him.
Once ripped off, he'd have taken his life since he could no longer plow Sif while Thor watches.
Knowing this, Odinson was about to use the full force of the Odin Power which gives greater control over Mjolnir to make him an eunuch and Bill realized it's not worth it.