Since going dry 3 weeks ago (really well, to be fair, very few accidents at all) DS has realised that saying "need a wee wee" can get him out of all kinds of situations that he finds really boring. For example this afternoon, we went to someone's house to visit for 20 minutes; he didn't like it and repeated "need a wee wee" non-stop, even when he'd just been taken. If we go shopping, in the car, anywhere, literally every 30 seconds he repeats it like a mantra, even the second he gets off the loo/potty he's asking to go again. He often specifies "weewee upstairs", which means that he actually wants to go upstairs to play with water in the sink.
The only time he doesn't do it is when it's just me and him here, and I put a potty in the corner and leave his pants off, so he knows it gets him nowhere.