Most dudes should know what a smoke bomb is, but for those who are a little less underhanded than the rest of us, let us lay it out for you. A smoke bomb is basically any kind of misdirection that'll deflect attention away from the real topic. We're talking tantrums that come out of nowhere, counter-accusations, and completely irrational behavior. If this is happening, you should be extremely concerned about what she's doing behind your back.
Recognize any of those? You should, because it's a classic move, straight out of the cheating-man playbook. Women are fully capable of doing the same, though, so you should be on the lookout. If a conversation or some innocent questions suddenly take a sharp U-turn, then you've gotten close to a painful truth - one that she doesn't want you to know.