Thanks all for your suggestions so far. I haven't made up my mind yet, will do tonight when DH is at work.
The last line is in there as DH is 1 of 6 (4 boys, 2 girls) children. His brother's wife is expecting their 3rd bub in April, 1 of his sisters' her DH has had a vestecomy. So that leaves a total of 4 possibilites, which is going to be very amusing for the 3 of us couples that know, to see if his mother can guess.