So first, I never want to downplay a public health alert - they are meaningful, and important. I'm sure that Ontario Health or whatever it's called shared the news of the syphilis outbreak because there has been a significant increase in cases.
But it's also important to keep in mind what "significant" means here. In 2021, Ontario had 2,678 cases of syphilis. (https://www.publichealthontario.ca/-/media/Documents/Surveillance-Reports/Infectious/2021/quarterly-infectious-diseases-surveillance-report.pdf?sc_lang=en) In 2020, there were 2,316 cases.
This has a chart so you can see how it's increased across Canada - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8889924/
That all said, there were 14,223,942 people in Ontario in 2021. That means 0.0189% of all Albertans had syphilis in 2021. (Feel free to double check my math - not what I'm known for.)
In any case, to get syphilis, you need to have direct contact with a sore. Even if I give you my talk about brevity, which I'm sure you've already read if you've seen my other responses, it wouldn't matter if she didn't have a sore.
Something else you've probably seen - guilt doesn't equal risk.
Really, I wouldn't worry about this at all. Oral sex on a vagina is incredibly low risk.