My boyfriend's comments freak me out.

Yesterday while walking on a sunny lake we was talking about several things and suddenly he started to ask me if I believed that someone has been killed and throw to the lake and no one have ever noticed that? I was like whaaaaat? Really random comment... And the he started to ask me more things about psychopaths and passional crimes and that stuff and if I believe that the murders get away with their crimes if they apparently are good persons...And I was like.. Ok? What do u mean? U wanna kill me and throw me at the lake? 😂 Maybe was just random conversations but still freaked me out a little bit.. And also sometimes when we go to a Sex shop or a store something sexual / playful he starts to tell me that I should pick some toys to use with my female friends.. And I'm like whaaaat? 😂 this has been many times and I'm starting to believe that my boyfriend has some twisted fantasies with me ... Should I be worried about or just let it as a random comments? what do u think girrrrlsss?😱