What's "homosexual behavior", and where/how would these people be experiencing it?
I am not sure how to answer this. In the context in which I am using the reference, I believe the person experiencing the discomfort would be best able to define that behavior (which makes her uncomfortable). Why are some people afraid of the dark? crowded spaces? Mother-in-laws? My point is that in many cases of exploring phobias the therapist does not outright dismiss the phobia, real or imaginary. Rather, they explore the phobia, rationalize the phobia and attempt to define the source (of the phobia). Only after a process is a phobe ready to release the phobia, if ever.
Now, so we don't get too far into the weeds, the generalization to which I am referring is the sexually-charged interaction between persons of the same sex. This could be anything from [offering to] buy a drink to intercourse. As to the where, obviously the dojo environment in this context, since that is the focus of the thread (I assume).
Hope somewhere in there is the answer you were looking for