It might be colostrum. Men lactate too sometimes. Just to be safe have the fluid checked by your doctor. Don't worry about it too much.
Get some hormone tests run, look for prolactin.
I had the same problem. Except i had a baby Dec 11 2007 breast feed for 3 months. 6 months later i started making clear liquid out of my breast when i squeezed my nipple. I called my OBGYN who asked me to come in. I went to her office. She ran a prolactin level which was normal. Because it was normal it is called Galactorrhea. They don't know what causes it. It is ok. Im and RN and talked to others at work who had the same problem. It is actually more common then u think. However, if ur prolactin level is high they will do furhter test for a pituaitary tumor. The pituitary gland is in ur brain and stimulates prolactin. Prolactin makes breast milk. At first i was freaking out thinking i had a tumor. From my research there is nothing they do for it but put you on meds for life to decrease prolactin. It is not your typical type of tumor that is cancer. Go see you doctor!! Hope this helps.