No.
As stated in other answers, Ricky told his father he was gay to disgust him.
What Ricky didn’t know, was his father had been harboring gay feelings himself, which he then tries to bring to fruition with Lester.
Once Lester turns him down and corrects his misinformation about being gay, the Colonel feels overwhelmed with guilt and shame brought on by internalized homophobia and murders Lester to assuage his own feelings.
Ricky couldn’t have possibly known his father would kill Lester.
Ricky knew him as a stern disciplinarian and a control freak, not a murderer.
movies.stackexchange.com/users/46297/M.Mat
According to the script, Ricky definitely did not rile up his father to get to get him to murder Lester.
However he did not even say those words just to hurt or piss off his father.
This is something that is not depicted in the movie properly but Ricky actually was trying to break free from his father for a long time and at that moment in the movie, he found out a way to do so.
According to the script - Ricky eyes the Colonel.
He's finally discovered a way to break free from his father, and he can't believe it was this simple.
If it wouldn't have been for the fulfillment of his long cherished desire to get out of the control of his father, Ricky, depicted in the movie as a street smart guy, would have avoided pissing off his father just for momentary pleasure because it would have then made his life even more complicated in the future.
movies.stackexchange.com/users/48771/Shashank
Ricky told his father he was gay to hurt his father by repulsing him the harshest manner he knew how.
Convincing his father he was gay labeled his father an ultimate failure undermining his self defined masculinity as a man and US Marine.
It also burned the bridge and insulated him from any future temptation to return home forcing Ricky to fend for himself from that moment forward, he was sealing his own fate of independence and thus began his ascension into adulthood.
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No, Ricky told his father simply to piss his father off, because his father was controlling and condescending, and he knew that would really bother his father.
He didn't know his father would kill Lester because of it.
movies.stackexchange.com/users/8071/Johnny Bones
No.
Ricky didn't tell his father
he was gay
so he could kill lester.
He just wanted to infuriate him.
Frank was gay.
As to why he was disgusted by it, he had probably been in complete denial about his true nature for years.
Many gay people are torn over their sexual orientation.
Adhering to a strict macho military image may have helped Frank mask his true feelings, and he probably considered gay people as being weak and loathsome, while denying he was one.
When he acknowledged his own homosexuality, he, in effect, despised himself and considered his life a failure.
He thought Lester was gay, a secret he's been keeping about himself for a long time.
When Lester spurned his kiss, he was humiliated and enraged.
So he killed lester
movies.stackexchange.com/users/51159/Sunilkumar Ramamurthy
During the scene where Jane and Ricky were talking about killing Lester in  American Beauty , Ricky zoomed into Jane's eyes. I understood this as a sign, that Jane was not actually joking about killing her father.  Do you think Ricky told his father, that him and Lester had sex, just because he knew that he would be pissed off and kill him? This would make sense, because Ricky was so obsessed with Jane and he knew she wanted Lester dead.
Did Ricky tell his father he is gay, so he would kill Lester?
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movies.stackexchange.com/users/59394/Rollo Tomassi
Ricky told his father he was gay to hurt his father by repulsing him the harshest manner he knew how. Convincing his father he was gay labeled his father an ultimate failure undermining his self defined masculinity as a man and US Marine. It also burned the bridge and insulated him from any future temptation to return home forcing Ricky to fend for himself from that moment forward, he was sealing his own fate of independence and thus began his ascension into adulthood. Ricky told his father he was gay to hurt his father by repulsing him in the harshest manner he knew how. Convincing his father of being gay labeled his father an ultimate failure. It also burned the bridge and insulated him from any future temptation to return home.
Ricky told his father he was gay to hurt his father by repulsing him in the harshest manner he knew how. Convincing his father of being gay labeled his father an ultimate failure. It also burned the bridge and insulated him from any future temptation to return home.