<human>: Ok, so let me start by saying that I love my girlfriend immensely.  We have common interests we can share, but we both enjoy having our alone-time (we're both introverts), so we haven't had any conflicts about that at all.  In fact, in our time together, we literally have not gotten in a single fight.  She's the kindest, sweetest, but also goofiest girlfriend I've had, and she'd make an ideal wife.

The problem, though, is I think with me.  I just don't really have any strong sexual desires towards her anymore.  As it stands, we have sex maybe once a month.  I don't even masturbate very much because I feel guilty about doing that and not having sex with my gf.  

The problem is, this was the issue I had with my previous relationships as well.  The sex was frequent and good at the beginnings, but after just a year or so, I seem to lose most all my sexual desire.  I still felt like I loved them, but I just didn't have an overwhelming need to have sex with them.  

As it stands now, the gf hasn't brought anything up, but I do remember her saying early on in the relationship that ideally she'd like to have sex at least once a week or so.  We still seem happy though - she always tells me how happy I make her and how everything is great, and I don't get a sense that she's lying at all.

But I feel horrible; like I'm not being a good boyfriend.

So I guess my questions are:

1)  Those of you in relationships, how often do you have sex?  
2)  Is what I'm feeling normal at all?  
3)  If not, do you have any suggestions on how I should proceed?

Thanks!

Can you give me the gist of the text in a nutshell?
<bot>: Relationship-wise everything is great - I just have a serious lack of sexual desire towards her, and it's something I historically have had a problem with.  Any advice or suggestions?