The following schedule should work for your bridge group, where the first couple in each set of 4 is the one who hosts.
(11 4 9
(1 5 12 3) (2 7 6 10)
(12 2 1
(5 6 11 10) (4 9 3 7)
(6 8 2 4) (10 12 9 11) (7 5 1 3)
(3 6 10 2) (1 11 4 7) (8 9 12 5)
(9 1 10 2) (5 12 4 6) (11 3 8 7)
(7 10 8 5) (4 3 2 9) (12 6 11 1)
(6 4 7 12) (3 10 1
(2 11 9 5)
(8 9 6 1) (4 3 10 12) (5 7 2 11)
(10 8 5 4) (1 7 6 9) (3 2 12 11)
(8 11 3 6) (9 10 7 12) (2 1 5 4)
No couple hosts twice in a row. 6 couples host 3 times, while the other 6 couples host 2 times. Pairs of couples will play together either 2 or 3 times. Hope that helps.