I don't know man, all it takes is a heat of a moment. I've noticed that Sam got a very steady romantic path with Sophia but Dylan could make a jump. All I'm asking is that is there clues or something that say who's gonna cross the line first.
Dylan will probably be last, not just behind Sam but behind the other main characters too. Probably behind the side-job people as well.
That said, Sam isn't going to get her in the next update either. Even if it gets spicy, which it will, someone or something will interrupt them before it goes too far. That's the standard thing LP does. A phone call when the 2nd side-job kids were groping her. Liam showing up when she was smooching Sam in the tub. The mailman showing when the maid was massaging her etc.
We know the first straight sex scene (not counting Liam obviously) is on day...16? That's a few years away at best.