My BF says that his stones get bigger from not ejaculate. So the last time we had sex I played near them a lot. I yanked on them and stretched them out and squeezed them and hit them and pulled them. He didn't enunciate anything, but did ejaculate. Do guys like this?
"Stones" don't catch bigger from not ejaculating, they stay the same size. Sperm cell are all that accumulate surrounded by the testicles, and they're microscopic, so no matter how many are present, it won't affect the size of the testicles. The juice semen determines the volume, and it is produced elsewhere.
Yes, I also love extreme "testicle" play. There is risk in it though. If you play with them not easy enough you take the risk of possibly doing long occupancy damage or you might cause atrophy (castration) of one of them. Be well thought-out!