Yes, well of course I probably have a different "slant" on relationships with "girls", and don't view such a matter in terms of being concerned lest they be critical of some inconsequential aspect of anatomy such as a foreskin. If any girl were, I would see that as an immediate demonstration that they are not a "keeper", but a "loser". I am therefore concerned that if you
see that as a problem of any significance, you might seem to have an underlying personality problem.
Note of course, that I say "critical of". I might in the first instance be just a little surprised if they were to notice
such a detail, as in some ways this implies knowing rather "too much" - being too
familiar with men's anatomy in a practical sense.
Given that the young lady did
make the observation that it was unusual, one might reasonably expect her in the first place to be curious
and ask for some explanation. Next, you might expect her to ask you about function, and finally, enquire as to whether she might be able to help you with your efforts to remedy the situation.
This would be the general course of a "serious" relationship - but is this not what you are seeking?
I was a little puzzled about your reference to "getting in the raf". Are you presumably meaning the RAF
? I am wondering what the connection could possibly be with your foreskin, and also what you mean by "hygeine(sic.) purposes"?