Judaism is a religion with some rules and teachings. One thing that they think is not okay is when a boy likes another boy or a girl likes another girl in a romantic way. This is called homosexuality.
Some people who practice Judaism think being gay is wrong because it says so in the holy book they read, called the Torah. They believe that it goes against what God wants us to do.
Other people who practice Judaism think being gay is okay and love thy neighbor. They believe that we should love everyone no matter who they love and that love is a gift from God that we should celebrate.
Like most things, there are different ideas about this in Judaism and people have different opinions.