My boyfriend lied to me about his age?

Me and my boyfriend are gonna be together for a year in November. When I first met him he told me he was 21 but I found out he’s actually 24 so he turns 25 next year. I am 19 and next year I turn 20. I don’t really mind about the age but rather why he lied to me and wasn’t honest from the start. He said he didn’t want it to seem weird but I was like why would it be weird I don’t care I was 18 when I met him. But now that I know he’s 24 I don’t care either just the fact that he lied. Should I be concerned about this or let it go. Is it wrong for him to have lied to me. I’m also getting a lot of shit for this. My sister told me that is wasn’t right he lied to me and he should’ve been honest. I’m not mad just kinda hurt he’d lie to me. I don’t know is it that much of a difference. It’s only 5 years and I’ll be 20 next year so it won’t be that bad. Am I being naive or too delusional. Be honest I need opinions.
My boyfriend lied to me about his age?
Post Opinion