a), you COULDN'T remain detached (you're not even able to do so now, without the sex);
b) she'd view it as you approving of her behavior, and "Making everything okay";
c) there could be serious legal consequences (you need to ask your lawyer about this. In some jurisdictions, consensual sex between the spouses after infidelity "forgives," legally, all of the past infidelity, therefore negating your ability to use it as grounds in any legal action.
d) Until your have has a full-panel STD test, and shows YOU the results (and repeats it six months later), you are putting your own health at serious risk if you have unprotected sex with her.
