Males can also lactate if they have elevated levels of prolactin (which can be genetic). It’s fascinating stuff, some cis guys can allegedly get “sympathy lactation” after their partners give birth. There are also quite a few other species of mammals that have males lactating over females.

https://www.scientificamerican.com/article/strange-but-true-males-can-lactate/

However, guys, if you do start spontaneously secreting fluid out of your nipples, I would suggest getting yourself to a doctor.