SB 9.9.35
yasman me bhaksitah papa
kamartayah patis tvaya
tavapi mrtyur adhanad
akrta-prajña darsitah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
O foolish, sinful person, because you have eaten my husband when I was sexually inclined and desiring to have the seed of a child, I shall also see you die when you attempt to discharge semen in your wife. In other words, whenever you attempt to sexually unite with your wife, you shall die.