Is it possible that a gay person's sexual arousal and desire for men is just a phase and that the person is not actually gay?

As far as your question goes; it depends on the person. I once had a friend who went around calling herself a lesbian when she was really just a super dramatic person who constantly went over the top, so she wasn't (and my entire family and everyone else agrees on this), but she called herself that for a period of time before the thrill of prancing around saying she was a lesbian wore off, now it's something else of course, but I would say yes, that was a phase and therefore depending on the situation it's possible for someone to go through a phase of exploration before settling down and deciding whether they're gay or not.

That said, if you feel truly, no drama included, sexually aroused and desire men, I would say you're probably gay. I always say what's safe is graduate highschool / be at least 18, have at least one relationship (sexual or not) with someone of the same AND opposite sex, and explore your options. You don't need to 'choose' your orientation right away, it usually doesn't work like that.

When children start puberty sometimes they can get confused over their sexuality. This is a natural part of growing up into an adult and nothing to be ashamed about. There is a curiOSity of what another person looks like under their clothes. The phase can last all through puberty. By the time you finish puberty you should have a good idea what you will go for, whether it being the opposite sex or the same, sometimes it can be both !