In love with a straight boy as a gender fluid person

Mez • +they/them+ If my name changes it’s just part of my identity crisis🙃

Title is self explanatory, but there’s more context. This boy was my first boyfriend, first kiss, first love, first person I came out to as bi, first person I came out as nonbinary(technically still true) to. We broke up over a year ago, more or less mutually, we both grew as people, he joined the marines and wanted to catch up before he left for basic. We had a great time and have been pen pals since. I’m falling in love with him again but I also realized that I’m gender fluid. We aren’t even together again(yet??), but I’m worried I might become his girlfriend or his partner, but I’ll never be his boyfriend. He was supportive with me being nonbinary but what if it’s different when I have a he/him day or month? When I start T and get a reduction? I’m not in a safe place to transition medically, but should I wait to attempt another try until after I can? What if it causes family drama? Should I just lay it all out for him? He’s had to restart training because of medical reasons so it will be at least a month (or another three because he had a relapse a week ago) until I see him again and this feels like a face to face kinda talk. I don’t want to wait around forever not knowing, or go to his graduation and drop it on him