Is it legal for a 20 year-old and a 16 year-old to date?
It is a strictly abstinent relationship and they are 3 1/2 year apart in age.
Dating at any age is not illegal in any state, regardless of the age of the parties. Sexual conduct, as the Ohio statute puts it, is illegal with a minor under the age of 16 years old.
Now, although the age of consent is 16 her parents may still not be happy about the situation and make your life miserable. Be careful for yourself and your girlfriend. Maybe ask her parent's permission to date. It may sound corny but it may open the door to good relations all around.
You can date at just about any age legally. However, if the relationship turns sexual there can be criminal consequences depending on the age of the parties involved. Under OH law, there can be no sexual assault or like offense if both parties are 16 years of age or older. That is because that is the "age of consent". In other words, that is the age when a person can legally consent to have sexual relations; no laws are broken.