I love humping my pillow!?

Ok this is embaressing but i love humping my pillow.....it just feels so good wen i put it inbetween my legs and start grinding hard and humping it...it just turns me on so much and gives me such a great orgasim....im 18 years old....is there something wrong with me? i mean i have a bf who i have sex with also its just i do it wen he isnt around..and i havnt told him so he doesnt know...cuz idk wat he would think about it....is there something wrong with me?!