(Check out Part 1 and Part 2.)
The Bait and Switch
Step 1: Locate a female. Preferably one with severe emotional issues who is going through a particularly vulnerable time and won't be able to enforce healthy boundaries. Caution: This may backfire if she's so mentally unstable that she violently attacks you later.
Step 2: Ask her out. The beautiful thing is that it doesn't matter if she says yes or no. If she says no, which she will...
Step 3: ...Carry on as though she said yes. As in, conduct the relationship in a way that looks exactly like dating. The key here is to use her own word: "friends." That word is like a magic license to treat her as outrageously inappropriately as you want. If she suggests including other friends, veto this immediately. Isolation is essential.
Step 4: Now that you've got her isolated, don't waste any time in obtaining extremely personal information. Schedule her therapy appointments on your calendar to be "supportive" -- since no one else can match your unhealthy level of attention, she'll become dependent on you. (The other beautiful thing is that it doesn't even matter if you're not smart or funny or interesting at all... just act unbelievably nice and she'll be under your control.) If she's having a bad day, make sure to seem more understanding than anyone else would ever be so that she'll keep coming to you. Stay in contact all throughout the day, or every other day at the least. Make her homemade soup when she mentions feeling slightly under the weather. Get all dressed up and take her out to dinner and the ballet. Hell, rent an airplane and take her flying if you can! You know she never gets to do such things, so she won't be able to resist. Compliment her dress... her hair... her eyes. Get more and more flirtatious slowly over several months so that she doesn't notice what's happening until you're holding her in a long embrace. As long as you still call her a "friend," she can't possibly get attached to you, but you get to feel like a hero. (One exception to the "act like you're dating" rule: if she insists on paying for herself, let her. No reason to invest in something temporary. You're getting a great deal, plus she'll be tempted to believe that you're respecting her boundaries.)
Step 5: Repeat step 4 until a new prospect comes along. Trade in the placeholder immediately. If she points out your place-holding behavior, turn it around so that you're the victim -- she is invalidating your lifestyle and that hurts! Admit no fault, and certainly don't apologize. Why should you? This person has ceased to be useful to you, so reconciliation is unnecessary. You got what you wanted... and guilt-free, because after all, you were just friends -- she said so herself! And you know what they say: "Words speak louder than actions." (Don't bother yourself with the ethics of gaslighting someone who already has literal brain damage from gaslighting... you have more interesting things to worry about now!)
Step 5: Charm this new person into marrying you as soon as possible -- before she can change her mind. Four months is plenty of time to turn an acquaintance into a spouse. Remember, the only thing better than abruptly merging your entire life with a near-stranger (and having a black eye in your wedding pictures) is to time it so that you're also starting a stressful new job and moving out of state where you lack the social support your questionable decisions certainly require.