I was just wondering...what would be the risks if my boyfriend were to ejaculate into bath water while he and I were fooling around during a bubble bath together. Can sperm live in warm, soapy water? What would you suggest we do after this happens? Drain all the water from the tub and either refill it or end the bath? 

The danger of causing an unintended pregnancy from sperm released into bath water, or the water of a pool or hot tub, is very small as long as neither of you pries open the lips of your vagina. Your vagina forms a fairly tight seal so that without any interference, it is unlikely that any of the bath water would get into it, and hence no sperm would enter either. But if he were to touch your vaginal area after ejaculating, then the risk would increase, particularly if he had some of his ejaculate on his finger and put it up inside of you. So if you are just going to lay in each other's arms, you don't have to change the bath water, but if there is going to be any further "fooling around" then it would be best to do it either outside of the tub or after the water has been changed.