pushing the jokes at the expense of character 
(ROOT (S (VP (VBG pushing) (NP (DT the) (NNS jokes)) (PP (IN at) (NP (NP (DT the) (NN expense)) (PP (IN of) (NP (NN character))))))))
(ROOT (S (VP (VBG ) (NP (DT ) (NNS )) (PP (IN ) (NP (NP (DT ) (NN )) (PP (IN ) (NP (NN ))))))))