Recurring urinary tract infection. Does it need treatment every time?

Yes. Treat latest UTI with correct antibiotics, then take preventative measures to reduce liklihood of further utis. Empty bladder after sex, shower rather than bathe, avoid thong or non-cotton underwear. Drink plenty of water & urinate 2-3 hrly, do not withhold & spread thighs with urination, avoiding urine trapping by labia. Control constipation. May need antibiotic prophylaxis or just after sex.