The Georgi-Machacek Model is arguably the simplest model with an extended Higgs sector that houses a doubly charged Higgs boson and can preserve the custodial symmetry. In this talk, I would like to discuss some features and consequences of the model, paying special attention to the phenomenology of the exotic Higgs bosons at the LHC. In particular, the vector boson fusion processes are important means to probe/discover the Higgs bosons. Latest LHC data are employed to constrain certain parameters of the model.