My friend's (16F) dad (38M) is trying to get her boyfriend (17M) court martialed for engaging in sexual contact with a minor. Both her dad and her boyfriend are in the U.S. Army and we are overseas in Germany. Can he get into trouble for this?

My friend's dad (who's an E-8 in the army) is threatening her boyfriend (who's an E-3 in the army) that he'll report him and get him kicked out of the Army because he had sex with her (she's still considered a minor). But this doesn't make any sense to me? Isn't a 17 year old also underage? Also, their age gap specifically is not even one year (she was born on May 2008 and he was born on September 2007).

Another thing to clarify is that her parents were not aware of their relationship. In fact, her dad is pretty much against the idea of her dating any soldiers (even when she turns 18). I don't know how they found out but as we're speaking, she's crying about this and hopes that he doesn't get into any trouble for this. I looked it up and the UCMJ age of consent is 16 so maybe he won't get in trouble for it? Idk,I'm not a lawyer. Soooo what do you guys think?