Green’s Dictionary of Slang

(US) infatuated, obsessively in love.

1886		Stephens & Yardley in Little Jack Sheppard 18: 🎵 Keep the ball a-rolling a-rolling When bent up on a spree.
1892		H. Garland Spoil of Office 40: That’s Miss Graham [...] she’s all bent up on Radborne.
1900		H. Garland Eagle’s Heart 231: She’s struck on you [...] I never saw her worse bent up over a man.
1979		D. Gram Foxes (1980) 174: ‘God, you’re really bent up.’ The boy shrugged.