Mate I can't help but notice one thing. Your talk like your Fiancé owns you.Yeah I understand their side. If i don't reply my Fiancé has had me ear off haha.
Allowed to open, and now she has had your ear off. Never mind the CPU tell her to chill or hit the bricks. This has all the hallmarks of a bad relationship the way you are talking.
Do I ask my other half before I layout hard earned on stuff yes I do, we discuss and if we can afford it or commit to paying it to off (it's not always beneficial to not use your credit card) then I buy, same for her...but the words allow.... and grief because something wrong? Nip that in the bud now, or walk away or grow a pair. It's not sexism or wrong to stand up for yourself respectfully, calmly, and without being made to feel bad.