I'm afraid that one day, you'll get bored of me. That I won't be as attractive to you, my personality won't be as interesting, flirting with me won't be as fun, spending time with me won't be as special, you'll have less to say when we talk, you won't touch me like you want me. There won't be anything new about me that will surprise you, & then you'll start to look for someone to replace me.