How can Edward Kiss Bella without harming her with his venom?

I really don't know! Maybe Bella and Edward don't open their lips whilst kissing? It's something I've thought a lot about because of SM's statement that all of a vampire's bodily fluids are replaced bởi venom. It's also made me think about when Renesmee was conceived (and the times when she wasn't, if bạn know what I mean). Edward did his thing, and since all bodily fluid is replaced bởi venom... It's quite gross to think about, but also quite a plot hole, if bạn think about it.

In the Twilight Saga, the venom has to get into the bloodstream for it to have any effect. Bella never had a cut in her mouth when they kissed, and Edward never Mất tích control enough to bite her.

It doesn't explain how he managed to suck James' venom out (at the end of the Twilight book) without poisoning her with his own, though.

I'm pretty sure bạn have to be bit bởi the vampire and there has too be open skin for it to go in her system. Also I'm sure Edward wouldn't go so far,