So, do you go back with an ex?
 Before striking back up with an ex, consider the following:

• You can't "go back" to an old relationship... unless you want the same results. Going back to an ex means actually means that you are starting a new  relationship with someone from your past. You have to release what you think you know and get to know them all over again.
• Don't jump into bed right away... especially if the sex was incredible. You'll risk repeating your old relationship by fooling yourself about the level of connection. 
• Don't focus on the past, unless you are reminiscing about good times. Past disagreements (or what broke you up) can be discussed, but then you need to leave it alone. 
• Above all, take your time. Let the new relationship reveal its own possibilities, and you'll see what's possible.