cereal monogamy 

The custom or practice of eating only one type of cereal at a time. Cereal monogamists view the casual alternation of cereals, or, worse, mixing different cereals in the same bowl, to be simply wrong.

Not to be confused with serial monogamy.

"I eat Cheerios for breakfast. I eat only Cheerios; no other cereals. Cheerios are the greatest thing since sliced bananas! Wait-- I'm out of Cheerios... time to get some more cereal... I eat Frosted Flakes for breakfast. No other cereals; just Frosted Flakes."
That's an example of cereal monogamy.

cereal monogamy by Grinning Cat January 18, 2015

Cereal Monogamist 

A person who eats the same cereal every day through the course of several boxes.

Phil: "Hey Kara, what do you want for breakfast?"
Kara: "I've been into those bran flakes for the last several weeks and I see no need to change."

That's a cereal monogamist.

Cereal Monogamist by MzBranFlake February 8, 2012