Of course she is. I'm dead certain that the male is a part of the gradual frog in a pot method of acclimatisation Mistress seems to be employing. She has an entirely platonic, brief, faintly friendly encounter with him, and then further encounters periodically. He's charming, handsome, disarming, and a contrast from the rough characters Mistress exposed her too earlier.
He's going to be the guy that fucks her first, and he was always going to be.
Been re-reading the series for the hundredth time over. The bit of dialogue about how she's reminded about her former unit really sticks out to me. It's funny how really innocent thoughts from long before transitioning make complete sense now, especially when there's desire on both ends. It's actually really sweet, just like the rest of this comic!