age difference laws

Ohio

my son had a girlfriend who was 15 and he was 18. she turned 16 in may my son will be 19 in oct. she is pregnant but she was sleeping with a 47 year old guy when she was dating my son. my son and her was together once. so i'm wandering if my son can be in trouble with the law,if [and big IF] the baby is his.

Yes, it is a possibility. If he was 18 and had sexual intercourse with a minor under the age of 16, he could be found in violation of 2907.04. In his situation, based on their ages, the violation would be classed as a misdemeanor offense. If the 47 year old is reported to authorities and he was charged, this would be classed as a third degree felony based on the age difference. The outlines these details. See the bolded sections below.

§ 2907.04. Unlawful sexual conduct with minor.

(A) No person who is eighteen years of age or older shall engage in sexual conduct with another, who is not the spouse of the offender, when the offender knows the other person is thirteen years of age or older but less than sixteen years of age, or the offender is reckless in that regard.
(B) Whoever violates this section is guilty of unlawful sexual conduct with a minor.

(1) Except as otherwise provided in divisions (B)(2), (3), and (4) of this section, unlawful sexual conduct with a minor is a felony of the fourth degree.

(2) Except as otherwise provided in division (B)(4) of this section, if the offender is less than four years older than the other person, unlawful sexual conduct with a minor is a misdemeanor of the first degree.

(3) Except as otherwise provided in division (B)(4) of this section, if the offender is ten or more years older than the other person, unlawful sexual conduct with a minor is a felony of the third degree.

(4) If the offender previously has been convicted of or pleaded guilty to a violation of section 2907.02, 2907.03, or 2907.04 of the Revised Code or a violation of former section 2907.12 of the Revised Code, unlawful sexual conduct with a minor is a felony of the second degree.