Since you want it...
It needs more detail. This will help add length and more imagery. For instance, maybe you could write a little bit about Frank's day at work, then lengthen out the before and during sex scene.
Also, a bit of better word choice would help :)
I hope you don't think I sound bitchy or something, it's just something I noticed.
Here's an example:
http://www.ficwad.com/story/30491
Author's response
yeah,I know I had to do that..
I only didn't do that cuz my parents could easily find out about this,and I'd get into trouble,cuz I'm 13 and stuff..
Right,I can remember that tip.Add more detail.Got it.