I think making love should be saved for marriage and only to make children. Inbetween our children, we have tried very hard to abstain. It's been nearly 9 months since our 4th son Malachi was born. Sex is for animals, love making for children in marriage.
But give up the thought of convincing evolutionists of their errors. The Bible says that those who deny the obvious evidence that God has provided in creation are fools without an excuse. He said also that because of the hardness of their heart, God gave them over to delusion and to think in depraved thinking patterns. (See Romans chapter 1). In light of this, it is silly to even attempt to demonstrate truth to such people.