Dating ex cousin?

Sooo. I can already feel I’ll be judged but whatever. When I was 13 I dated a 20 year old, we lasted on and off for a few years, at this point I don’t even count the relationship bc that’s totally disgusting. Anyways, I’m now about to be 20 and his cousin, through adoption and I have been talking for quite some time. Would it be wrong if we pursued a relationship? Idk