If men could give birth, lots of attitudes would vastly different, but I especially think there would be less hangups and judgments about sex. Women are put on pedestals, not to be sullied by dirty sex, because they are "supposed to be" mothers. Men have long been able to stick their dicks anywhere they want because they won't be saddled by a pregnancy. Motherhood became more revered than sexuality, for women.
The world opens up... when you do.
Oh, oh, can't you see? Love is the drug for me. ~Bryan Ferry
"Love is that condition in which another person's happiness is essential to your own." ~Robert Heinlein