Welcome in H.C.M.
In connection to your query about recurrent sore throat
and swollen sublingual glands by oral sex
with your sex partner who is HIV negative.
and submandibular lymphadenitis
are due to direct infection reaching to your mouth from genital of your sex partner.
As far as spread from one to other is concerned it is due to contaminated genitals, so if anybody is having HIV than other sex partner may get infection after having contact immaterial of intercourse or oral sex.
You are at present are advice for-
1- Culture and sensitivity of saliva.
. & HIV.
3- Urine examination ( Routine & Microscopic ) and C & S.
4- Fnac from submandibular lymph node.
I hope above asnwers your query.