I met a girl (white) from Spain around 26 years old on a dating app, we had a good time, she seemed well educated and had a privileged upbringing. One thing led to another and I ended up back at her, we hooked up at her place but only had oral sex, there was a time a she was on top of me and we were grinding on each other. I have a concern that in this instance the tip of my penis may have slipped in and put me at risk of contracting an STD or HIV. I asked her if that happened and she insisted no it didnt, however, I do not fully trust her as a person.