Having problems with jeans!!?

I have a lot of jeans. and every pair i wear makes a weired sound when i walk. like the inner thigh or the crotch area rubs together or something and makes this weird sound. It's kind of embarring since the weird sound kind of sounds like farting. I'm not fat or anything, but do you have the same situation too? please tell me any ways that i could prevent that and any advice.