to throw oneself into someone's arms, typically as a physical expression of affection or relief

孩子一见到出差归来的爸爸，就飞快地跑过去投怀送抱。

idiom · to offer oneself to someone proactively, often with seductive intent or to gain personal advantage

他原本以为她是真心爱慕，没料到这只是她为了求职而投怀送抱。