When I first heard the title the first thing I thought about was how Tyler Durden in "Fight Club" describes his men as Space Monkeys. So I agree with the sex-interpretations, but it doesn't seem to me like it is described in a positive way. He describes himself as a space monkey, "Ready to sacrifice himself for the greater good. (from "Fight Club"), so he feels like he is just used by his girlfriend or whatever so she can have her fun until she finds anything better ("Like you let me down before").
When I first heard the title the first thing I thought about was how Tyler Durden in "Fight Club" describes his men as Space Monkeys. So I agree with the sex-interpretations, but it doesn't seem to me like it is described in a positive way. He describes himself as a space monkey, "Ready to sacrifice himself for the greater good. (from "Fight Club"), so he feels like he is just used by his girlfriend or whatever so she can have her fun until she finds anything better ("Like you let me down before").