Not sure what to do! Help

Alicia

I’ve been in a relationship for a year an a half now. I love him and can see a future with him. There’s just one problem..before i met him i was used to dating guys with a big D and he doesn’t even have an average sized D. I’m not quite as pleased as I would like to be. So I find myself fantasizing about one of my exes quite often. I haven’t cheated on him and I never would but I’m tempted and can’t help but think about what sex would be like with another man. Sex is a big deal in relationships and if you aren’t satisfied it could lead to problems. What should I do? Should i stay with him with all the temptations I’m going through? Break up with him to get this out of my system then go back to him? Or break up with him for good an explore other options?