There is lots of Profanity,I think it should desserve 4/5 language, there ARE some brittish pop-culture referances, some adults also drink beer and wine, that word "t--t" gets it a TV-MA because it basically means "vagina" or a huge A--hole (as in jerk)
so thats why it's TV-MA-L, or why people don't use words like that (or c--k, c--t and ni---r)