The phrase "fuck you" can be used in many different ways:
1)It can be used as a high level of offensive matter whereas it is intended to hurt another person.
2)It can also be a way to express your sexual desire over another person of opposite or same sex.
3)It can express a deep repulsion or the desire for another person to leave.
4)Finally, it can be used ,in a amiable accolade, as an unobstrusive jealousy, where this jealousy is mostly friendly.
Dialog examples with according definitions:
1)"Fuck you, you unorthodox being."
2)"I want to fuck you, will you come up into my room?"
3)"Fuck you, I will have to ostracize you now for wanting to (2)fuck me."
4)"Fuck you, you killed me again."