Husband's Fetish

Do any if you ladies have a husband/bf with sexual fantasies that you don't exactly like? My husband's is that he's into cuckolding. I've told him that I don't mind role play in the bedroom but I don't know that I could actually go through with it. We'll talk about it and after I express my feelings he will let it go for a while but he always seems to bring it back up. It makes me feel like I'm not enough for him and I don't know how to deal with this. Any advice greatly appreciated....