It’s not entirely risk free. What you plan on doing.
For example the riskiest part is the unprotected oral sex that risks gonorrhoea, Syphilis , Herpes and a lower risk of chlamydia. Of corse this depends on if she has any of these she probably doesn’t but you can’t be sure.
Even the protected vaginal sex still risks all be it low risk of HPV, Herpes and Syphilis.
It wouldn’t be fair for me to say no risk. I’m not saying the risk is high, but it’s present.
If you go ahead you will need to regular test to keep everyone safe in the triangle. And of course if you do get something you will need to tell your partner. Is the risk worth it?