You can blame this rant on Todd.

This is actually my brother-in-law's theory, he ranted about this years and years ago to me and I completely agree with him, and because of that, I have had to bite my tongue through more conversations with idiot guys than I can count. Most recently I had to sit through a formal dinner with one particular idiot, and I was almost bleeding by the time the night was through. Since he was a co-worker of Sgt. G's, and I had known the guy for all of 10 minutes, I refrained from embarrassing him in front of everyone. (which in retrospect was a great accomplishment for me, since as some of you know, I don't have much of a filter, and I had consumed several Jack and Cokes throughout this meal)
Have you ever noticed that some guys will complain that his girl is never in the mood, or that she will "hold out" when they are fighting like that is the girl's fault, and not his? I just don't get that. Guess what Dude, if your girl is holding out on you that is noone's fault but yours...and the rest of us are just going to make fun of you if you willingly share that information. Any guy who complains that his girl "holds out", or never seems to be in the mood might as well hang a big sign around his neck announcing "Not that good in bed". Did it ever occur to you that women won't deprive themselves of something that is great for them just because they are mad at you? Newsflash, we don't. Why on earth would we punish ourselves just because you are acting like an moron? Here's a thought, work on your skills. Find out what makes your girl tick (because here's a surprise- we are all different) and make sure she is having a good time, every time. If you do, I can promise you that she will actually say she is sorry first- just to get back into bed. She will magically be in the mood as often as you are, because DUH, we like to feel good too.
So, Sgt. G's co-worker, here's a little advice: instead of putting all this effort into tracking your girl's 'cycle' in an attempt to know when you might get lucky (which by the way, is NOT proper dinner conversation), try being good at it. It's not that hard. Being good at something pays off more than being lucky any day. And if you can't manage to do that, could you at least keep your shortcomings to yourself?