It’s likely that a urinary tract infection (UTI) is coincident with, but not necessarily caused by oral stimulation. Menopause includes the loss of estrogen, which leads to the thinning of urogenital tissues--which include the vagina, vulva, and urethra. Because those tissues are thinner, they can be more fragile and susceptible to “trauma.”
We don’t think of sex as “traumatic,” but the activity can cause minor tissue damage. And sex can introduce bacteria to the bladder via the urethra, which can lead to bladder infections. That bacteria may come from hands, saliva, toys… anything that comes into contact with fragile urogenital tissues during sex.
And note that UTIs are often more frequent for women after menopause, whether they’re sexually active or not. You can reduce the chances by using a lubricant during intimacy to minimize “trauma” to tissues. Empty your bladder soon after sex; that may flush out bacteria before they proliferate and become an infection. Therapies like localized estrogen and Osphena, which improve vaginal tissue health (with proper pH and increasing cell layers), also benefit the urethra. And, if you’re prone to UTIs, you may find it helpful to take a dose of oral antibiotic with sexual activity.