Are there any sources that the following case would constitute causing others to sin?
A person addressed a nonreligous Jew about keeping kosher, and tried to make him keep kosher. The non religious Jew said he doesn’t keep kosher but does not eat meat and cheese. The religious Jew replied “You might as well eat meat and cheese if you're eating nonkosher.” The non religious one took this advice and started eating meat and cheese.
Does this mean that the religious Jew caused the nonreligious one to sin, and will receive punishment every time the latter eats meat and cheese?