How to do an action if an optional boolean is true?

It is possible to achieve that behaviour with .filter(b -> b):

spouseIsMale.filter(b -> b).ifPresent(b -> System.out.println("There is a male spouse."));

However, it costs some brain execution time seconds to understand what is going on here.

For good order

if (spouseIsMale.orElse(false)) {
    System.out.println("There is a male spouse.");
}

Clear.