Ok, so I'm not sure if this fits into this category or not (if not please tell me where to post it and i will do so)

My fiancee and I have been seeing each other for over a year now and as we all know occasionally the topic of her past sexual experiances does come up in conversation (to me or to somebody else when i'm in the same room).  I'm the guy that was never popular in high school, doesn't have many friends, and was never given the time of day until college started.  I'm 21 years old now as is my fiancee.  She was the girl that everybody wanted all through highschool etc...She brings up her past sexual experiances multiple times a week and each time I ask her not too as I would just rather not know what she did in her past as it makes me a bit jealous.  I have told her this honestly and she has appologized to me and has said she'd attempt not to talk about them but she does it weekly.  I guess it's just her nature but it sometimes offends me because in my head it seems she enjoyed herself more before she met me and it makes me wonder if I'm doing something wrong.  Any advice would be greatly appreciated.  Also lately within the last 4 months the sex has become nearly non-existant.  She constantly tells me that she is going through a "dry spell" and that they happen in females.  I have never heard of this before and it makes me worried.  Also I have read the experts advice on this and it only mildly calmed my fears of her seeing somebody on the side.

Thanks

How explicit was she with her past sexual encounters?  I ask this not to be creepy, but because it could serve as a learning experience for you.  I'm implying from your post that you're not as sexually experienced as she is, and perhaps that is somewhat responsible for both the dry spell and her comments.

Here's a few more questions to ask yourself:

Do her past partners sound sexually adventurous (different locales or positions, toys, role-playing, etc.) and do you consider yourself to be equally as adventurous?

Back before the dark days of the drought, how was the sex?  Did it last a while, or was it always a quickie?  Did you have an open line of communication with each other, and offer suggestions without feeling embarrassed or insulted?

Did she seem to enjoy the sex, or was she always trying to get out of it?

I'm by no means trying to indict your sexual prowess, but it seems to me as if this girl is accustomed to a certain level of performance that she may or may not be getting. 

Maybe she's talking about her old sex life to drop hints to you about how things could be improved.  Even if she's not consciously doing that, you should still capitalize upon the opportunity to find out more about what she likes and surprise her.

Also, and this one is the most important point, I don't believe dry spells happen without a reason.  As Midori very correctly points out, she could be busy, stressed, or just not feeling well.  She also might feel like there isn't enough romance being attached to that animalistic act, and wants you to slow down.  Alternatively, you could be too soft when what she really wants is a raucous romp.

The point is, you have to talk to her about it. Explain that she's obviously had a healthy sex drive in the past, and ask her to open up to you about why that's died down.  If she's not forthcoming with a reason, be willing to offer the hypothesis that she's simply not satisfied and express your commitment to improving for both your sakes.  I've been in a dry spell before, and the only way that it can be resolved is through communication.

One way to deal with jealousy regarding her past is to acknowledge a simple truth: her past is directly responsible for bringing her into your life.  Consider this carefully -- her past relationships, her past sexual experiences, her past mistakes, they are all part of what makes her who she is and part of the events in the timeline of her existence that brought her to you.  So in a way, you should be thankful for them.

Now, let's back away from intellectualizing this and go straight for the truth of it all -- Envy.  If you are sexually insecure (or being made to feel insecure through her inappropriate references), then ask yourself why this might be the case.  Listen to her feedback and what she is saying to gain clues; women say things for a reason.  If she is saying these things while, at the same time, having a "dry spell", be very suspicious.  Women who are genuinely disinterested in sex do not, also, talk about sex often.  She could be dissatisfied and horny and using you to vent about it, but not using you to get off when she needs it.  This could be problematic for the relationship and speak not to jealous/envy issues, but to trust issues.

Also on the vein of trust - - you mention flirting.  It is true that there are some types of women who just naturally flirt, and many men are just naturally hard-wired to flirt with women as a matter of basic conversation.  However, women who are interested in a committed relationship with a single person and who are ready to 'settle down' are not going to be involved in flirting; they will shy away from it, flat-out turn it down, and never ever respond to it.  She could just not be ready, and your sex life (or lack thereof) may be an indicator that she's not being fulfilled in your relationship on some level (sexually, emotionally, etc.).

You would do well to listen to her feedback, try to initiate adventurous/spontaneous sex, and consider doing some planned kinky/fantasy sex.  If she does not respond or if fights ensue, then, you have some serious relationship issues that need to be resolved and they may stem from some potential infidelity or trust issues that are happening that may not be out in the open.  Be cautious, and most of all, be prepared for the can of worms that might ensue.  But if she's worth fighting for (and I suspect she if, for after all, why would you be posting this if she weren't?) then, be ready to pull out all of the stops to get down to the bottom of this and take care of business.