Death at a Funeral

Aaron (Chris Rock) and Ryan (Martin Lawrence) are two brothers whom are totally different in personalities and views on life. Aaron, the older son, is a well-mannered and hard working young man, married to Michelle (Regina Hall), and still living at his father's home. When their father dies, it is up to Aaron to organize the funeral and give the eulogy. Aaron and Michelle have been trying to buy their own home and have children but have been unsuccessful. Aaron envies Ryan because Ryan is a successful writer, while he has not had his novel published, and resents his brother because he would rather spend money on a first class ticket from New York to Los Angeles than help him pay for the funeral expenses.Meanwhile, Aaron and Ryan's cousin, Elaine (Zoe Saldana) and her fiancee Oscar (James Marsden) are on their way to pick up her brother Jeff before heading to the funeral. To ease Oscar's nerves, she gives him what she believes is Valium. Jeff later reveals to Elaine that it is actually a hallucinogenic drug he's concocted for his friend. Chaos ensues when Oscar hallucinates that the coffin is moving; he knocks it over, which pushes the body out of the coffin.At the wake, Aaron is approached by an unknown guest, a little person named Frank (Peter Dinklage), who reveals himself to be the secret gay lover of his deceased father. Frank shows Aaron photos as proof and threatens to reveal them to Aaron and Ryan's mother, Cynthia, unless he is paid $30,000. Aaron tells Ryan, who suggest Aaron pay the money because Ryan claims he's buried in debt. When Aaron and Ryan meet with him to pay him, Frank starts to deride Aaron's ability as writer and Aaron refuses to pay. Frank gets angry and tries to leave the room when Ryan attacks him and as a result, both Aaron and Ryan tie Frank up to prevent him from leaving. Norman comes in and sees what happened. He gives Frank what they also believe is Valium to try and calm him down and Jeff tells them it's not Valium.While Jeff and Norman, who are supposed to be watching Frank, get distracted by Uncle Russell, Frank jumps off the coffee table and hits his head. With Aaron, Ryan, Jeff, and Norman believing Frank is dead, they plan to put him in the coffin. While everyone is outside watching the naked Oscar on the roof threatening to jump because he saw Elaine unwillingly get kissed by Derek, Aaron and Ryan put Frank in the coffin.Elaine calms Oscar down by revealing she is pregnant. With everyone back inside, they continue the eulogy. While Aaron awkwardly tries to do his speech, Frank starts banging on the coffin and suddenly emerges from it. The pictures fall out of his pocket and Cynthia sees the pictures, screams, calls Frank a bastard, and starts to attack him. Aaron yells for everyone's attention as he tells them that his father was a good man with flaws like everyone else.At the end, Aaron and Ryan say goodbye to everyone for attending while Ryan gets a ride to the airport by little Martina, who Ryan has been trying to get with all day. Aaron and Michelle are finally alone and going to try and have a baby and also decide to stay in his father's house. Aaron asks where Uncle Russell is and Michelle tells him that she gave him what she believes is Valium to calm him down. In the final scene, Uncle Russell is on the roof naked.

Question: Why is Oscsr threatening to jump off the roof?
Answer: He saw Elaine get kissed by Derek; He saw Elaine get kissed by Derek