Is it illegal for a 16 year old to have sex with a 23 year old?

In Maine, the age at which a person can legally consent to have sexual relations is 16. This means, that if a 16 year old consented to have sexual relations with the 23 year old, (except under certain circimstances "C" and "D" outlined in bold. below) he would not be found in violation of "254 Sexual abuse of minors"; however, if the parents of the minor child object to the 23 year old's relationship with the 16 year old and take legal action to prevent it, there may be other serious non-sexual offenses the 23 year old could be found in violation of. The parents have a legal right and obligation to protect their minor child and maintain control over the minor child's behavior until the child turns 18.

Certain exceptions in the law change the age of legal consent from 16 to 18 years of old.
Chapter 11: Sex Assaults

§254. Sexual abuse of minors

1. A person is guilty of sexual abuse of a minor if:
A. The person engages in a sexual act with another person, not the actor's spouse, who is either 14 or 15 years of age and the actor is at least 5 years older than the other person. Violation of this paragraph is a Class D crime; [2001, c. 383, §21 (amd); §156 (aff).]

A-1. The person violates paragraph A and the actor knows that the other person is related to the actor within the 2nd degree of consanguinity. Violation of this paragraph is a Class C crime; [2001, c. 383, §21 (new); §156 (aff).]

A-2. The person violates paragraph A and the actor is at least 10 years older than the other person. Violation of this paragraph is a Class C crime; [2001, c. 383, §21 (new); §156 (aff).]

B. [1989, c. 401. Pt. A, §5 (rp).]

C. The person is at least 21 years of age and engages in a sexual act with another person, not the actor's spouse, who is either 16 or 17 years of age and is a student enrolled in a private or public elementary, secondary or special education school, facility or institution and the actor is a teacher, employee or other official in the school district, school union, educational unit, school, facility or institution in which the student is enrolled. Violation of this paragraph is a Class E crime; [2001, c. 383, §21 (amd); §156 (aff).].

D. The person violates paragraph C and the actor knows that the student is related to the actor within the 2nd degree of consanguinity. Violation of this paragraph is a Class D crime; [2003, c. 138, §2 (amd).].

E. The person violates paragraph C and the actor is at least 10 years older than the student. Violation of this paragraph is a Class D crime; or [2003, c. 138, §2 (amd).]

F. The person intentionally subjects another person, not the actor's spouse, who is either 14 or 15 years of age to any sexual contact and the actor is at least 10 years older than the other person. Violation of this paragraph is a Class D crime. [2003, c. 138, §3 (new).]
[2003, c. 138, §§2, 3 (amd).]

2. It is a defense to a prosecution under subsection 1, paragraphs A, A-1, A-2 and F, that the actor reasonably believed the other person is at least 16 years of age. [2003, c. 138, §4 (amd).]

3. [2001, c. 383, §21 (rp); §156 (aff).]

4. As used in this section, "related to the actor within the 2nd degree of consanguinity" has the meaning set forth in section 556. [2001, c. 383, §21 (new); §156 (aff).]