I know i get sick of the same ol pooty-tang after a period of time. Of course the more you like the girl the longer you can go without havng to change up the order. When things begin to get boring thats when u gotta make changes. Try adding some role playing or something else that spices shit up!!!!
I am very picky about who I get in a relationship with so I guess my opinion is a little bit askew. This sounds really really bad but I won't go out with a girl that I don't think is at least an "8" or a "9" so its kinda hard to get tired of top notch ass.