They go "hand in hand". It really doesn't matter how you say it - "Love for Sex" or "Sex for Love". It's liek saying in Nepali-"Kalay Kami ya Kami Kalay". There were few interesting thoughts from you folks. From where I see is, and Few Conclusions I came here are as follows --

1. The presence of one without the existence of other is incomplete or rather say irrelevant.

2. They equals to eachother. ie. Sex = Love or vice versa.

3. One is directly propertional to other. ( except in few many cases).

4. The ratio should be in a balance state for well normal functioning of the systems.

5. Increament in one for long period of time brings discomfort in the systems.

6. Finally, There is a "Proportional Constant called "B" ( balance) which shifts automatically to either one to make the total balanace equals.

Also, there are few more findings  

1. Women enjoys sex more than Men, while Men enjoys Love more than Women.

2. Men remains active in Sex for long time than Women, While Women remains active in Love for long time than Man

3.Both Love and Sex can be used as a tools to overcome frustration  and depression.