Based on the information you provided and after reviewing Article 134 of the MCM I do not believe the adultery charge can be applied to your situation in that the young lady was not married. With regard to other punishment it is possible but typically unlikely. The only way I see a charge coming about is if you were to have an altercation with the other service member or in some way do something that is inappropriate and violates the UCMJ. It is possible he could contact your chain of command and present them with the evidence you spoke of. It this occurs you may get called in by the 1SG or Commander to have a rather embarrassing discussion on the matter so you might want to be prepared to calmly explain the situation to them.
