<human>: Can you summarize the given text in a few sentences?

My wife and I have been together for 10 years, married for 8. When we met, the sex was great and of course I expected that we wouldn't stay in the 'zone' forever but I never realised how much she would change over time...

Currently, we only have sex once every 10-14 days. If I try to initiate any kind of intimacy (kissing, fondling) in the subsequent days I get told to stop bothering her, that we only have sex the other day, etc.

In addition, her attitude to both oral and anal have completely changed. When we met, we did both frequently. Now anal never happens and I have told in the last year or two that "blowjobs are for birthdays"

Since, even for my birthday, I didn't get a blowjob last year I made some comment about wanting one the other day. The following day, my wife told me that if I bought her two presents she wanted (value of about 100 pounds) then she'd give me one.

And this is depressing me greatly. It feels like my wife isn't that interested in me. And I'm trying to cope with sexual frustration (watching porn, fantasising about people I know).

I've tried talking to her about it and she just tells me that blowjobs are what women do before they are married. And she is happy with our sex life as it is. But I'm constantly tempted to stray, to reclaim some of the passion that's missing from my life.

Any advice, very welcome!
<bot>: When we met, we had lots of sex and she enjoyed (or seemed to) blowjobs. Now she's telling me I need to buy her presents in exchange for them...