Numbers 5:13-14

13and sleeps with another, but it is concealed from her husband, and she is undetected, even though she has defiled herself, since there is no witness against her, and she wasn’t caught in the act;

14and if a feeling of jealousy comes over the husband and he becomes jealous because of his wife who has defiled herself — or if a feeling of jealousy comes over him and he becomes jealous of her though she has not defiled herself —