My first girlfriend was several months older than me, so there was a time during our relationship when she was 18 and I was 17, and I made jokes about it being a scandal. I don’t think she thought I was as funny as I thought I was 😅
But I would only be wary about an age gap if one partner is several years older. Differences of months are not concerning. A person in their 20s dating a teenager, though, that is a red flag.