+1 for putting the kink in the title. In general, be blunt about what you want; people will only click on threads that look interesting to them, and if they do click, they won't stay on the page for long unless there's something that catches their eye. Neither the title nor the first paragraph of your thread tells me anything about what you're looking for, let alone that you're looking for a relatively niche kink.
I hate using my own RTs as examples, but it's worth comparing your title and introduction to a similarly themed (long closed)
request I put up years ago. Note how it's immediately clear what I'm looking for: I want an RP featuring this kink, and this flavour of that kink, and only then I get into other preferences. While that might be too "in your face" for some, there's a good chance they're not into that kink anyway -- no loss there. Those who
are into it, however, will instantly know that I'm someone who shares their interest, and will have a reason to read on.
That said, while I won't say cuckolding is a particularly rare kink around here, it definitely suffers from the phenomenon where the malesub-demand is far far greater than the femdom-supply. While I think everyone's advice will already help a lot, it's also worth considering if you're interested in playing the female side of the dynamic -- if you are, I can guarantee your inbox will explode within a day.