When does morality begin, and when does it end? I think scientific awareness is a good replacement for morality. This is like, a cutting edge economical discussion in some scientific circles. I think it is possible to quantify the amount of good or bad you do with any action, roughly, and while this base of information obviously isn't scientific it still holds weight in the real world where physics hasn't carried us yet.
Before I digress any further, I simply mean to say that it still isn't possible to nail down particulars regarding time and place although space and gravity seem to be pretty well worked out, thanks to physics - the life sciences are obviously very successful, but the theoretical ones are equally important and I personally find economics to be the last great frontier of morality, which is the last great frontier of mankind.
You're not replacing morality with science. You're just replacing morality with another form of ethics: utilitarianism. That's nothing new: Bentham died almost two centuries ago. Morality isn't exactly a science. Please don't pull a Sam Harris.
I've always found it to be amusing that those that go through life/their younger years perpetuating the idea that one good romantic partner is somehow worth more than many frivolous sexual encounters always seem to be the ones that have had very little of said encounters...it's almost as if the notion of waiting for a soul mate is a defense mechanism against poor skills with the opposite sex - at least for some men anyway.
Yes, it's fucking hilarious that people who don't actively seek frivolous sexual encounters didn't have many frivolous sexual encounters