Is it normal that he wants a blow job all the time ?

i have been married for 3 years have been with him for a total of 10 years , now when we first started oral sex was a big thing i did not mind giving it back but now it has become the center of our intimicy he wants it all the time all day long and even before we start to have intercourse and always ends up with me finishing him off with oral sex is it normal !