get under someone's skin

Idioms  

1. Irritate someone, as in She really knows how to get under my skin with her nagging . This expression no doubt alludes to burrowing or stinging insects that cause itching or similar skin irritations. [Late 1800s]

2. Obsess someone or affect someone's deep feelings, as in Jean's really gotten under his skin; he misses her terribly . Cole Porter used this sense in his love song, “I've Got You Under My Skin” (1936).

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