5x3 question

SPOILER FOR S5 AHEAD

I just finished S5 ep 3 and haven’t gone any farther yet (NO SPOILERS PLEASE!), but am wondering- why didn’t Clark tell his parents that Jor-El only give his life back if he took his powers back and if someone he loved would die? I can guess it’s not wanting to hurt Martha and Jonathan or make them worry, but this has me BROKEN :(