I think its specifically him realising when he marked Brett, like it was he was in rutt, and Brett was being gorgeous and he felt safe / trusted him
Like the lights / neuron pathway bits is the "mark" itself
Thank you this is a great break down! I was confused a little at first but that makes sense
the thing I'd like to add: he didn't mark brett, but imprinted on him, which is a way more vulnerable position to put yourself into. i just thought it's an important nuance ╮(￣▽￣)╭
Okay so basically he throws him out, and then thinks about the last time he had a rut when Brett had a broken rib and used the safeword.
Assumingly, the thigh fucking is from then and its Hayden feeling sad because he thought tht was a step in them being equals