Eyes followed the descent, though quick, his eyes seemed to slow everything down in slow motion, and as he began to spin around to turn to her, he felt the curse and jolted sideways, still trying to turn, but managed only to move into it, flinging himself into a crazed 360 spin.
Swearing audibly, Montague only managed to pull himself out by closing his eyes tightly, focusing not on the dizzying force and swirling views, and on his body, his equilibrium, his hands on the wood. Centering himself he managed to lift the front of the broom, pulling up and had he been lacking a mask- would have spit angrily.
Instead, he darted, low to the broom once again, wand out, summoning with a harsh tug the bombs attached to her broom, the zoomed towards him and his hand reached out catching one easily, tucking it as if a quaffle (flashes for a moment of Quidditch, rushing the opposing team), and lowering his body further, wind resistant zipping along him before he threw with all his might- the round object towards her, hoping to set it off on her.