My only cautionary word is this, to people considering chancing it....
On extremely rare occasions, yes, you do get unusual, exceptional bettas that can survive together. Maybe for a short time, maybe for life. However, these animals are the EXCEPTION to the rule, and in the overwhelming majority of situations, fish WILL be injured or killed. And as a pet owner, you have a duty and responsibility to do everything within your power to protect your pets from harm. Why, then, would any responsible pet owner chance something so blatantly dangerous when they have been informed that there is a high risk of their pet being harmed?
Now, johnny.t had been misinformed. Thankfully, he has been very fortunate, and started a tank not only with the bad mix of males and females, but with fin nippers and bettas. He is very lucky that none of his fish have been wounded or killed. But just look at numerous other posts on this forum and others where inexperienced fishkeepers have put malesand females together; the results are almost unfailingly negative.
jammerone, you have now been informed, so keeping your bettas together would at this point be irresponsible, wreckless, and very probably dangerous to their lives. As others said, 4 hours is nothing; I've known people with even all female tanks whose fish snapped and killed one another after over a YEAR together. Please, just seperate the two fish; you are more likely to be the rule than the exception, so do not endanger the lives of your fish just to see if it could work.
Hope that wasn't roasty... I'm trying to make a strong point to newbies without being too unfair to johnny.t