Short Answer:  Sex w/ hubby after legal separation = reconciliation in the eyes of the law, even if it's just once.  All separation time is erased and the clock starts over.

Long Answer:  My lawyer gave me what I consider the best advice ever regarding sex after separation:  "If you are 100% certain that you still want to be in a sexual relationship with this man after you know for a fact he has slept around, you'd better (a) make him wear a condom and (b) be prepared to kiss all the time and money you've invested to date in the divorce process good-bye."  Think about it:  Your husband committed adultery.  He had sex with another woman.  Likely it wasn't "safe sex" either (my laywer said 90%+ of men who cheat do so without protection, often proven by the frequent discovery by the cheated-upon wife that hubby's paramour is suddenly pregnant).  You have proof positive he considers you nothing more than a disposable sex partner.  Knowing that, do you still want to sleep with him?

It's normal to feel lonely, confused, etc. after separation.  Heck, a part of me still loves StoopidEx, and we're coming up on 2 years post-divorce (he had no less than four affairs I knew about and probably a lot more that I never knew, but as far as I know, only the last one was sexual), and I took him back after three of his affairs (but we did move to safe sex practices 100% of the time until he agreed to get tested for STDs).  But if you're serious about getting a divorce, if your marriage has deteriorated to the point where it's no longer worth saving, you are just asking for trouble if you even think about resuming marital relations.  You're worth more than that.  You're not a disposable sex toy.  You're worth far more than that.  Just remind yourself of that regularly.

Good luck.

First of all how did you feel when he cheated on you? I have been married to my stbx for 30 years and no after I found out he cheated I stopped sleeping or having sex with him. Do you feel that you can trust him not to cheat again? I agree with mtnyly get him tested before you do sleep with him and have safe sex.Good luck!

In VA once you cohabitate with a cheating spouse it is considered forgiven. Now, if he cheats again and you don't have sex with him  you have grounds for audltry. I just really haven't figured out how it helps in a divorce.  It seems the law could care less.  Been there done that, thinking that would fix marriage.  I was married 32 years.

Married 20 years, I know it's tempting, but; it is a false sense of connection.  Sex is what they want and need for self-satifaction.  That is why they cheat.  They are still on their pre & and adolescent "hunt".  Once they conquer, they are done, do you really want to be another conquered prey?  I didn't once I saw it from that perspective.

I would like to also add..I know that you are attached to him. I was in a similar situation with my ex. The intimacy is hard to let go.
We attempted to reconcile for 2 years , not living together but were intimate.
If I had to do it all over again...there would be no intimacy. None. I felt like we needed to in order to stay faithful while we were trying to reconcile. It is an important part of a marital relationship. That is when our best communication was..afterwards.
It was a tremendous waste of time. I was holding on to something that was never going to work.
Just be careful and again protect yourself.

I have a friend who had an affair. She was advised by her lawyer that if she didn't want the adultery brought up in court to "attempt " to reconcile with him. She stayed with him a few months after that, slept with him and the adultery was not and could not be mentioned.
For your peace of mind , do not sleep with him. If you are trying to reconcile, do so with out sex. If in the case you do decided to sleep with him then have him get tested FIRST.Protect your self!!!
Laws may vary by state. The above was in VA. It may be different where you are. It is not worth losing everything for.