Phil, didnt they teach you in high school algebra that -(-) equals +? You must've been chasing skirts. lol
Right. Some cash and euro settled ops trade at a discount to intrinsic all the time. VIX ops are a good example of this. So are ops on supply side products during backwardation. In such cases the time value of an option is negative and converges to spot with the passage of time. In those cases, the effect observed is synthetically equivalent to being +gamma and +theta simultaneously.
Deep ITM european style option will often trade below parity. They price time and vol out of the option to create a negative carry and it rises to parity as expiration approaches.