Transgender patient and a dilemma

So my coworkers and I encountered a bit of a dilemma with a transgender pt. 16 y.o. born female transitioning to male. The pt preferred to be called he so I will refer to them as he. He was a 16 year old who definitely appeared as a female outside of a small amount of chin hair, male haircut and clothes. He was a psychiatric pt who needed a shower. We always send our pts to shower with a chaperone since we are not a psychiatric unit, we are an ER who holds overflows from time to time, and we don't have a shower on unit obviously. With females we send a female security staff member, with males we send a male staff member. We encountered a dilemma here. Obviously the pt was a minor first off. Then we all just looked at each other in confusion as to what gender to send as a chaperone. Do we send the male or the female security?? I mean for the pt's safety and the security staff safety, this was a tough call. The pt could have brought accusations against the staff untruthfully AND who knows anymore the security could have assaulted him! It's like what do you do?? What do yall think? Have yall encountered similar situations? I just feel like we in healthcare are going to be encountering things like this more and more and it could get a bit sticky.