Problem with pygame not switching the mouse image

[Mondaythe1st]

So I lied about going to be. Seems I have to double post too...
But I got this to work

######################################################
def mouse():
    global mouse_cursor
    global b1
    ex = pygame.mouse.get_pressed(0)
 
    if b1 == False: #not clicked
        if ex == (1, 0, 0):
            mouse_cursor=WnY
            b1 = True           
    elif b1 == True:  #clicked
        if ex == (0, 0, 0):
            mouse_cursor=WnR
            b1 = False  

There's very noticeable slowdown in the program on each click though.
Is there a way so it doesn't lag?? I mean it's just 2 variable checks, and 2 variable sets...