A man with a beer puts his arm behind a smiling woman.
A man with a beer puts his arm around his girlfriend, who's smiling.
The fact that a man puts his arm behind a woman doesn't imply the woman is his girlfriend.
exists e2 e1 x1 x2 x3 x4.(behind(e1,x4) & n_woman(x4) & Actor(e2,x4) & v_smile(e2) & Theme(e1,x3) & Actor(e1,x1) & v_put(e1) & n_arm(x3) & of(x3,x1) & n_male(x1) & with(x1,x2) & n_beer(x2) & n_man(x1))
exists e1 s1 x1 x2 x3 x4 x5.(around(e1,x4) & Theme(s1,x5) & a_smile(s1) & (x4 = x5) & n_girlfriend(x4) & of(x4,x1) & n_male(x1) & n_male(x1) & Theme(e1,x3) & Actor(e1,x1) & v_put(e1) & n_arm(x3) & of(x3,x1) & with(x1,x2) & n_beer(x2) & n_man(x1))