Xor comparison in one-time pad cipher

Question

I am using one-time pad cipher. When we use same key on two texts (m1, m2) then c1⊕c2 = m1⊕m2. Why isn't it the same? What am I missing?

Here is example:

m1: dog  - 011001000110111101100111
m2: cat  - 011000110110000101110100
key: pas - 011100000110000101110011

c1: soy  - 011100110110111101111001
c2: ral  - 011100100110000101101100

m1 xor m2:  11011101111101011011100111111
c1 xor x2:  10110000010000000110000100