Yes you were. Having sex with a child, no matter how pretentious, precocious and arrogant is rape, exploitation and abuse. Any person 21 who does that is an exploitative child molestpor should she b hung by his balls in public.
A child cannot consent. If local laws set the age of consent that low (are there such jurisdictions?) then that is a mistake on the part of the community.
In a lot of the US, possibly even the majority of it, the age of consent is 16, not 18. Everybody seems to think it's 18 everywhere, which is basically not true but the perception is mostly due to the Federal child porn laws, which do make the age of 18 critical - but for being in porn, not for consenting to sex, which is an issue of State law. There has been a lot of uncertainty induced into the system in the past couple of decades by touchy-feely advocate types pushing laws that muddy the waters with provisions like "16 is legal but only someone not older than 19," and similar language from the Rube Goldberg School of legislative arts. The Federal law pegged the age where they felt like, without reference to the states except to set it no lower than the highest age of consent in use anywhere - 18.