"It could be that women coincidentally smell my terrible BO when I mention I want a long-term patner, but I doubt it."
It could also be that your signal of interest is the catalyst for them deciding to act on their pre-existing feelings of doubt. Perhaps they were already harbouring doubts but didn't voice them until you, essentially, forced them to decide.
My anecdotal evidence is that, as you point out, a relationship formed on desperation covered up by acting tends to end the moment the acting dissolves. This implies that sustaining such relationships means acting for the rest of your life, an outcome you probably want to avoid.
Given that your criteria for a "success" are, essentially, "going on dates" and "having sex", I'm not sure whether you're content merely maximizing those two factors or actually care about the resulting relationships being fulfilling, but I'll give you the benefit of the doubt and a...
Adding to this, basically every word can be used as a sexual euphemism, especially for genitalia. So it doesn't surprise me at all that the centroid, which is sort of the average of all words, can be defined as such.