sniff around
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source: [GJ部の皇紫音たちが探偵の真似をしているGIF画像｜無料GIF画像検索 GIFMAGAZINE 489587]
sniff around
informal investigate covertly, especially to find out confidential or incriminating information about someone.
sniff (a)round: ｟くだけて｠ (情報･秘密などを求めて)かぎまわる.
sniff around someone
to try to get (someone) as a romantic partner, employee, etc.
｟主に英･くだけて｠ 〈人･組織などが〉〈恋人･客･従業員など〉を手に入れる.
e.g. His engagement hasn't stopped him from sniffing around other girls.
e.g. Rival companies have been sniffing around her for years.