Is it normal to date someone 3 years younger?
Depends.It depends
Yes, a three-year age difference is usually no big deal when you’re both adults. If one of you is underage, though, age, maturity, and local laws matter a lot more.
If you’re both adults, three years is a pretty small age gap. What matters more is whether you’re at similar stages in life, treat each other well, and want the same things—not whether your birthdays are exactly three years apart.
If one of you is underage, don’t brush off the gap: the legal rules and power imbalance can be important, especially if the older person is an adult. Keep clear boundaries and make sure everything is legal and freely chosen.