using a

if <touching [mouse pointer] ?> then
set size to (30) %
end

to make sprites bigger when you hover over them but for some reason still happens when another sprite is in the way? how do i fix

The sprite in front is in the way if it's also touching the mouse pointer. If you find that first and store it in a variable, you can then do something like this:

if <<touching (mouse pointer v) ?> and <(sprite in front is touching mouse) = [false]>> then
set size to (30) %
end

I already made this demo that's basically what awesome-llama said so I'll send it anyway. To be clear, this works because sprites and clones on the front layers run first, activating a variable that blocks later clones from being allowed to detect the mouse.

DEMO

thanks. didn't want to share the project because its not done