So your thinking that maybe this guy either materbated and then got the seman on the condom which was on his finger and then masterbated you? Or he cut himself open got blood all over the condom which was on his fingers and then masterbated you. Or he kept seman or blood in the bottle marked lube and then put it on the condom which was on his finger and masterbated you?
Please read what I have written a couple of time and you will see how crazy that question was you just asked.
Thanks for the reply.
What if he deliberately used semen or blood when i couldnt see what he was doing?
No risk from fingering. please try and read the hundreds of similar question this site has.