fall over oneself
fall over (oneself)
To expend an inordinate amount of energy or effort to do something, especially as a means of gaining attention or approval. John is such a brownnoser, falling over himself to impress the teacher. My parents fell over themselves trying to seem cool to me and my friends. It was pretty embarrassing, to be honest.
fall (all) over oneself (to do something)
Fig. to rush eagerly and awkwardly to do something. The boys fell all over themselves to open the door for Sarah. Larry fell over himself trying to help Sarah on with her coat.