Potty Training

We started potty training B the first week of August. He is pretty much 'peepee' trained. He loves to go potty outside. He even asked, "Mom, are plants thirsty?" (see the picture below) The second day we were in training he tried to go potty at Sonic. We were enjoying some ice cream at the outside tables. B and his friend were running around playing in the grassy area between where all the cars park. The next thing I know B is standing in the grass with his pants down around his ankles saying, "Mommy, I need to peepee." I was laughing so hard I could hardly talk. Austin got him to pull his pants back up, but a few minutes later he did it again. We decided it was best to head for home and the privacy of our own little potty seat.

We have yet to poopoo on the potty seat. I am trying everything I know to do to get him to go in the toilet instead of his underwear. I've tried bribery (ice cream, all his race cars, and James the train). I've tried making him uncomfortable (cold showers every time he goes in his pants, he has to wear those ugly plastic underwear over his training underwear). We've watched movies, read books and talked about. I have even forbidden him to watch Bob the Builder (his current favorite) until he poops in the potty. I have yet to take away t.v. completely since that will be very hard on me. Any advice from you experienced potty trainers would be appreciated!