Cut 'em down, pull all the leaves off, feed them battery acid. That should stress the hell out of them. LOL. Why do you want to stress your plants??? Crazy pissed off girlfriend trying to ruin the boyfriend's grow???
By any chance have you just read the book "Sensimilla"? I remember reading that like 20 years ago and one of the "grow tips" was to stress the plant to get it to produce higher levels of THC. It is complete bullshit. Dont stress her, sweet talk her like you want to rip off her leaves and smoke her brains out.