Is there any way to slim my thighs without losing butt or breasts?
Never heard of any way
Google "spot reduction" (the idea that you can reduce or lose fat from one spot)
You'll find that it's a myth. You can work the muscles of a body part but where the fat goes/comes off is based on genetics.
You can tell ppl this till you're blue in the face and they will STILL believe someone who tells them what they want to hear, like "just do ten lunges per day and drink lemon juice with cayenne pepper and oh yeah buy my thing I'm selling that will help with your exact problem"