If you're feeling like you're cheating then perhaps you need to slow things down. Personally I think it's ok since you're only technically married. But if your guilt is kicking in then take a few days by yourself and see how you feel after that.
As for the kids, they're teenagers! If they can't handle getting themselves up for school by now then they're going to have a lot of problems once they're out of the house. Being a good parent means teaching them to be responsible for themselves. They missed the bus this time so next time they'll know better. Remember, if you choose the actions you choose the consequences.
If you love somebody, set them free. http://tinyurl.com/2empx2g
