Fiance & I don't agree on money

We are not struggling with money. We both make a decent salary and have a budget with quite a lot of buffer, because neither of us have any expensive habits. We don't drink or go out to clubs.

But he always acts like a cheapskate. We went out for lunch (most of the time I cook at home) and I wanted to get a $2.99 dessert for once - I never do. He made a huge deal out of how expensive it was. When we go shopping, he will make loud comments about how expensive things are, even when they really aren't. We got in an argument at Walmart about whether tissues are necessary! I have horrible allergies and constantly blow my nose. I guess he expects me to just carry around wads of toilet paper.

I'm so frustrated. His mother is the exact same.