(First I will also be posting this on other subreddits where it might be found beneficial.) I often read about those who use MDMA as an aphrodisiac having troubles of one sort or another, most commonly unable to achieve orgasm within a realistic amount of time or at all. Beyond this there are those who can't even get started, which must be an awful tease to say the least.
My answer?... 2C-B. Let me take a quote from Erowid.org "Perhaps the best use that has been found for 2C-B is as a synergist with MDMA. When taken together, the MDMA pushes the non-specific 2C-B reaction in a more warm and emphathetic direction. Because 2C-B is a psychedelic drug, and therefore not fully predictable, its action can take the user in many different directions. But if the set and setting are right, 2C-B can enhance the desire for sexual orgasm during an MDMA experience. The synergy of the two substances can on occasion be a true aphrodisiac. [Eisner, 1989]"
Shulgin himself in his famous book PiHKAL also writes, "The most successful reports have followed a program in which the two drugs are not used at the same time, nor even too closely spaced. It appears that the optimum time for the 2C-B is at, or just before, the final baseline recovery of the MDMA."
With all of this in mind, I hope it can be found useful to some to help break the barrier or, if you find MDMA alone to be enough, that your expierence might enjoy a breath of new air and be of increased ecstasy. For more about dosage and the particulars see --> https://www.erowid.org/chemicals/2cb/2cb_faq.shtml and please do your own research!
My tip for lovemaking, stick penis in butt and pee. Is that how u sex?