Bye Bye Love

 is a side quest in Fallout: New Vegas.

Detailed walkthrough
NOTE: It seems that there is no way to complete this quest without passing a 50 speech check.

This is a quest that begins in either the Gomorrah casino and hotel or the Vault 21 hotel. If the Courier goes into the Gomorrah courtyard, Joana will begin a conversation. Passing a Medicine (50) or Speech (75) check will initiate dialog that will eventually have Joana talk about Cachino and Carlitos. She will offer the player 200 caps or sexual services for taking the quest (the second option is only available if your character is male, or a female with the Cherchez La Femme perk). Or the player can talk to Carlitos in Vault 21, pass a speech check about why he left the Omertas and Joana. Carlitos will give the player 200 caps upon accepting the offer to help him and another 200 upon completion.

The player has the option to help Joana, before or after choosing to have a sexual encounter, by finding Carlitos (located in the diner of Vault 21) or letting her know Carlitos is looking for her. After some running back and forth between Joana and Carlitos, the player can agree to help Joana, and two of her fellow prosititutes escape to Freeside to join Carlitos; the agreement being to wait until between 12AM and dawn, being Gomorrah's most busy hours, before attempting the escape. Carlitos advises the player to get some backup before attempting the escape, as he knows two guns-for-hire that owe him a favor. This gives the Courier the option to recruit Big Beard and Little Beard who are located in the Atomic Wrangler Casino. Talking to a disguised Joana in the lobby triggers the escape itself and is literally just walking the disguised girls from the Gomorrah lobby through the front doors of the casino and out of The Strip. However, always let them pass through the doors and gates first as not doing so may result in the quest failing for leaving the girls behind.

Once you meet up with the hired guns and Carlitos, 4 or 5 Omerta thugs will ambush the group. The player can either go into combat with them or with high enough Strength (8,9) or speech (75 and 85) skill, avoid the fight altogether. Carlitos and Joana must survive the confrontation or else the quest will fail. If successful Carlitos will thank the player and ask if there is a way to repay the kindness. From here you have a choice between receiving 200 caps or accepting a simple thanks. Alternatively, if you talked to Carlitos first and you have a high enough Barter skill (65), you can get another 400 caps on top of the 200 at the start.

From here Joana will thank the Courier and mention a sinister plot she's heard about from Cachino about the Omertas. The How Little We Know quest will initiate if you haven't found this quest already.

Bugs

 * Carlitos sometimes doesn't appear in the game, making the quest incompletable. To fix this on PC, use the following console commands:, ,
 * Another glitch can happen where Joana disappears after you talked to Carlitos. To fix this glitch on PC, go to the courtyard and use the following console commands:, ,
 * Sometimes Joana is in the alcove just below her room, precisely under her bedroom door. The quest marker will point to her door making you think she's in her room when you're in the courtyard and then she's in the courtyard when you've entered her room, this can be fixed by improving the game performance.
 * Another glitch can render this method useless because if you tried spawning Joana in the courtyard with the console it will make her disappear once she's entered her room after she's told you to follow her to her room. If you spawned her inside her room, she'll keep asking you to follow her to her room.
 * Another glitch with this method that can occur and also renders this method useless is that Joana doesn't lead the way to her bedroom when she is supposed to, then continues doing her thing. Starting a conversation has her tell you to follow her to her room, but she doesn't move. This doesn't happen when she's not spawned from the console, So a script is most likely deleted when she's spawned with the console.
 * This glitch can happen if you complete How Little We Know before taking Joana out of the Gomorrah.
 * Sometimes if you leave without Joana and the disguised hookers following you the quest immediately fails for leaving them in the Gomorrah.
 * Another glitch might happen where after telling Joana the escape plan, Joana and the disguised hookers arrive in the Gomorrah lobby but don't follow you. Leaving to Freeside without them results in failing the quest a few hours later. One solution to this problem is to start combat with Joana, leave the Gomorrah, then go back in and restart dialogue with her. Otherwise PC players can use the following console commands:, . After that, exit the Gomorrah, enter Freeside, and Joana and the disguised hookers should appear next to you resuming the quest.
 * After running back and forth a few times the dialogue option to get Joana to run away might fail to appear, you'll need to have a high enough speech skill to convince her.
 * Killing the bosses with Cachino during How Little We Know can cause you to fail this quest.
 * The bug that makes either Carlitos or Joana impossible to find occurs if How Little We Know was completed. If you completed that quest, then it's impossible to finish this quest because the main characters are missing and spawning them with the console only takes you to the escape where the quest stops working when Joana wont leave the Gomorrah. This can happen even if you haven't completed How Little We Know.
 * When leading Joana and the disguised hookers outside the gate to Freeside, the securitrons posted outside the gate can become hostile, attacking all included people. Killing them gives infamy for the strip but letting them kill Joana fails the quest. The reputation for the strip can be fixed with the following console command:
 * When Joana and the disguised hookers are waiting in the Gomorrah lobby the game can crash when exiting the strip, fix it by allowing all four of them to leave first.
 * After escorting Joana and the disguised hookers to Freeside; Carlitos might not appear making the quest un-completable when Joana, the disguised hookers, and the Omerta thugs stand around and do nothing. Killing the Omerta thugs won't work since Joana and the disguised hookers still need Carlitos to appear to advance the quest dialogue. Reloading the auto-save from when you entered Freeside can fix this.
 * After going past the securitrons and turning the corner; Joana and the disguised hookers will reach Carlitos, then they'll stop in their proper spaces, then do nothing. If you talk to Carlitos he will thank you then say "wait, what's that.." and point into the distance and nothing will happen, the thugs don't appear.
 * Killing the Omerta thugs can turn the other Omertas back at Gomorrah hostile, causing failure of all quests associated with them.
 * Sometimes, after completing this quest the Omertas may become hostile.

Behind the Scenes

 * The name of the quest is a reference to The Everly Brothers song of the same name.