you can't. you never could, not even in the good old days. though divorce was not as common, adultery was. i will say this though, i wouldn't have it any other way. with all the fear of divorce and lawyers and pain it could cause, it makes it even more beautiful that someone is willing to take the chance.
if you are in love and really feel loved, jump in baby and take the chance. all you can do is live it right, if it fails, then you've done your best.
i've done it 4 times. i got it right with #1 and #4. #1 passed away at 18, one month after our wedding, # 4 is with me now and will be till one of us dies. 2 gave me a couple gorgeous and now successful children, and 3 was a bad idea. all in all i am a happy man and have been tested for a long time.
i hope you are loved and can love enough to take the plunge