Suggest Remedy For Foul Smell From Vagina

Im 58 year old male. Im one of those old guys that still have the foreskin attached to his penis. For years after sex if do not wash very well and pee. The next morning I have this nasty order. How I've kept this at bay over the years is that I use an antifungal cream. The same used for athlete's feet. (Tolnaftate 1%) However, my question Is Why is that. After my new girlfriend and I have sex her vaginal will start to smell just like my penis Why? Is ph? I know its not STD. I was married for 34 years. My x wife did not have this trouble. I know the new girlfriend did not cause the problem. Anything I can tell her to do? I can do? Or use a condom the rest of my life.