I need help on what to do

My partner and I have been together for 2 yrs and we have a daughter together and another one due in feb

And he has been lying to me about small things at first his fathers fridge he sold behind his fathers back his father keeps come to my home looking for it and he says that he will drop it off to him then it was money for car parts for his car then it was my car he lied about getting it pink slipped and $300 went missing when I booked my car in to be fixed then he lied about about his fathers mower sold it behind his fathers back then my father bought a fan for my house it’s gone missing

Idk what to do

No he does not do drugs he smokes cigarettes he just can’t keep up with financing his addiction