[keulege]

If the TS is scared of HIV (and rightly so), then the best option is to get that WL to test for HIV antibodies (almost instant result, window period notwithstanding). Must get WL to test, you test no use hor. If she is positive, then get on PEP immediately. If this happens a few days ago, then it is probably too late. If she is negative, then at least psychologically you will feel better.

For the other STDs, just do a screening. Most of them won't kill you even if you get it. At least you can get early treatment. Usually will be ok lah, unless one is so sway.

Probability of infection = probability that WL is infected x probability of successful transmission in 1 encounter = not 0 but low lah.

I am curious how come it breaks. Not enough lub?