The guy spent the whole night bird-dogging a girl at the party, even though she kept avoiding him.

bird-dogging 是由 bird（鸟）和 dog（狗）组成的复合动词，字面意思是"像猎犬追鸟一样紧追不舍"。这里用作比喻，形容某人像猎犬追踪猎物一样执着地追逐另一个人，带有贬义色彩，暗示这种行为可能让对方感到不适或困扰。