callery pear

(Adjective) Pyrus calleryana: A tree common in China or Vietnam. In the spring, it blooms into bushels of white blossoms. A person may first think that this tree is beautiful, but upon inspection with the nostrils it becomes clear that the trees true intentions are quite rank. The tree will release a foul smell into the air withing a 200 yard radius, destroying previous admirations.

Can be used to describe a relationship or situation, but most commonly a person, that has attractive attributes but when analyzed better turns out to be worse than previously thought.

Person:

That girl is a real callery pear. She's hot, but has a really bad personality. I'd stay away from her.

Relationship:

Me and that guy didn't really turn out well. We both thought that we would be great together, but it just turned out to be a callery pear.

Situation:

(1) We were gonna just make out, but things got a little to far so I had to back out. I didn't want it to end up in a callery pear.
(2) I really wanted to take that class, but the teacher was so bad that it ended up being a callery pear and I transfered out.