special relativity - How can time dilation be symmetric?

Suppose we have two twins travelling away from each other, each twin moving at some speed $v$:

Twin $A$ observes twin $B$’s time to be dilated so his clock runs faster than twin $B$’s clock. But twin $B$ observes twin $A$’s time to be dilated so his clock runs faster than twin $A$’s clock. Each twin thinks their clock is running faster. How can this be? Isn’t this a paradox?