Do Not TouchBy Rabbi Jack Abramowitz
G-d then outlined the forbidden sexual relationships. No one may even initiate romantic activity with such relations, let alone consummate it. These relationships include: one’s parents, stepmother, sister, grandchildren, aunts, daughter-in-law and sister-in-law.
Also forbidden: a mother and daughter or a grandmother and granddaughter. (This does not mean simultaneously; it means that one may not marry a woman and then later marry her daughter.) One may not even marry sisters, although it becomes permitted to marry a sister if the first one passes away.
One may not be intimate with a woman from the time her period begins until she attends the mikvah. And not only is having relations with another man’s wife forbidden, doing so makes her forbidden to her husband! (This is only if she’s a willing participant, not if she’s coerced. And no, she can’t marry the adulterer, so it wouldn’t be an easy way out of her marriage.)
Of all idolatrous practices, G-d tells us that the most reprehensible was the service of Molech, which involved a person passing his children through fire. This especially ticks G-d off, so don’t do it!