Dictionary
Fujoshi Lexicon: one true pairing | ˈwən ˈtrü ˈper ing
O.T.P is an Otaku-slang phrase (Fujoshi Lexicon). The abbreviation refers to the phrase "one true pairing". When you break it down it has the word one which singles things out, the word true as in the persons truth, and then pairing that is two separate people. This is a phrase that is generally seen as a romantic idea to pair up two individuals that would be seen as a couple that would be heavily suggested by a person as the one true pairing.
Definition of O.T.P
1: One True Pairing is a pair of characters a person thinks work well together.
2: A pair of characters that are chosen by a person who thinks that they must be together as a holy divine pairing.
Usage
Early usage: In its early use there have been people who referred to it as a way of having a sexual connotation of two males paired up together as a gay couple. It would be known as the sexual definition that would be known more for its usage in pairing arguments of arguing which was a better pairing of seme (top) and uke (bottom).
Modern usage?/Recent usage?/
Sentence
"When watching Naruto, I like Naruto and Sasuke. Their my O.T.P."