It sounds like you're experiencing a power struggle in your home right now and the kids are winning!  It can be very frustrating when you feel like your kids are disrespecting and taking advantage of you.  It's easy to get overwhelmed and look for the easiest and quickest solution.  However, we all know that quickest isn't always best.  It's great that your kids have a father figure in their life.  You questioned whether you should get back together with your husband for the sole purpose of getting the kids to behave.  Ideally, a child is raised in a two parent home, but remember that your first husband can still be a positive male influence in their life without being present 24/7.  There are many behavioral techniques you can try before you resort to living in a situation that you are not happy with.  

Start by setting very clear rules in your home.  Sit down with the kids explain each rule and regulation such as cleaning up after themselves, bedtimes, accepting decisions, etc.  Then explain what the consequences will be when they don't follow the rules.  The key is to actually follow through with the consequences when you say you will.  Additionally, remember to give lots of positive praise when they do follow the rules.  Try implementing a system in which they can earn stickers or small prizes for following the rules for an entire day or week.  
This will give you a good start.  Remember that it will take time to change their behavior, so be patient.  

If you would like to talk to a parenting crisis counselor more about your situation please call the Boys Town National Hotline. We're here 24/7 and would be happy to discuss your situation with you.  

Take Care
Boys Town National Htotline
1-800-448-3000