Sexual 5 here.
According to Beatrice Chestnut's sub-types, I am a Counter-Type 5.
If studied, her theory on 5s shows Counter-Type 5s as the most romantic of the 5s--not in a 'I cried 25 times watching Sleepless in Seattle' or 'My favorite flower is the rose; favorite gem is a diamond as an engagement ring.'
Rather, Counter-Type 5s look for one-on-one, deep, lasting, idealized... and often, perhaps usually never find a relationship that measures up.
This fits me, yet I did find the best person for me that I came across:
Friend to best friend to lover to husband--29 years; 24 married.
My husband, early on in our relationship, said that I was "too intense," and that word kept popping up through the years. He doesn't say that now; perhaps he's grown used to that about me. ¯\_(ツ)_/¯
I am very private, very introverted, but with my husband--I am very open in ways I am never open with anyone else.
Occasionally, throughout my life--even for short periods of time, I've clicked with people, and that is what I called it--long before I read about types or sub-types, or any of this kind of personality theory, which described the sexual 5 as needing 'to click' with one other, or a series of others.
I am often mistaken by those who don't know me, i.e. on line, as a 4 which is absurd, or a 6 which is more believable, yet the Counter-Type 5 has aspects of 4s and 6s, remaining a solid 5.
"The name of the subtype, Confidence, is about building a bond with another (or many others on a one-to-one basis)..." [excerpt from Beatrice Chestnut's on Enneagram.]
I don't know how much nurture, e.g. my infant and toddler foster care (poverty, violence, neglect...) has to do with it, but a 5 fits me.