going to a house party and watching the host defend himself against a frothing ex-girlfriend 
(ROOT (S (VP (VP (VBG going) (PP (IN to) (NP (DT a) (NN house) (NN party)))) (CC and) (VP (VBG watching) (S (NP (DT the) (NN host)) (VP (VB defend) (NP (PRP himself)) (PP (IN against) (NP (DT a) (VBG frothing) (NN ex-girlfriend)))))))))
(ROOT (S (VP (VP (VBG ) (PP (IN ) (NP (DT ) (NN ) (NN )))) (CC ) (VP (VBG ) (S (NP (DT ) (NN )) (VP (VB ) (NP (PRP )) (PP (IN ) (NP (DT ) (VBG ) (NN )))))))))