Was he cheating or what

My fiance has a drug n alcohol problem it's not everyday only when he gets paid so he wanna me to do some but I said no he had already ate me out like 3x I had been drinking so I was sleepy so I gave him a little head and I ended up falling asleep so I wake up and hes gone I'm like wtf was gone its like 1am so I'm thinking he probably went a bought some more drugs so i call n call his phone no answer so finally he video calls n shows he with a co worker from work so he says hes on the way home finally after about 45mins he never comes so I go looking for him towards where he told me he was he said the only people was there was his co worker n his co workers girlfriend n somebody else so I call him he still isnt picking so finally I head back home I'm furious now cause u been gone along time just to be getting high so i call him again and he answers I'm screaming hollering hes telling me it isnt no girl he isnt doing anything this and that so finally I'm upset more hurt than anything so he gets home I tell him I'm done n he can leave he packs his stuff goes outside text the guy telling him to come n get him I reach for his phone hes fighting me over the phone what dont u want me to see so his co worker n his co worker gf come to get him drugs make him really freaky plus with alcohol the whole thing seems weird like they were doing more than getting sounds like some kinky shit