[ike]

Yes, he's very likely to be trying to take this down with less than the nuts. But that alone isn't enough justification to raise, he has to be likely to have a hand good enough to call but not a full house. In fact, since you're paying off raises, you have to get more than twice as many calls from losing hands as raises, situations where you raise and he mucks his bluff you've gained nothing by raising. I don't see why its obvious that he's on exactly two pair or trips that often.