i think 00q is a polyamorous relationship with mi6, in which m is treated as a metonym for mi6. it's not me saying q or bond have a sexual relationship with m, but that m[i6] is their priority in life and the primary figure in their relationship. they both understand what its like to have this deep affection and need and reliance and trust for m[i6], a type of devotion where they know they've willingly exposed all their most vulnerable parts to m[i6] and told m[i6] to treat them as they like. it's this deep ongoing romance, every other relationship is an affair.
"Not necessarily," said Bond. "Matter of fact I'm almost married already. To a man. Name begins with M. I'd have to divorce him before I tried marrying a woman. And I'm not sure I'd want that. She'd get me handing round canapés in an L-shaped drawing-room. And there'd be all those ghastly 'Yes, you did--no I didn't' rows that seem to go with marriage. It wouldn't last. I'd get claustrophobia and run out on her. Get myself sent to Japan or somewhere." - diamonds are forever, ch. 22
ik ive posted this quote before but it's so prototypical of bond's mindset imo. it's a joke, but it's also serious. m is his #1. relationships with other people are suffocating and boring to him, and his refuge from all of that is m's instructions. i'm sure i've posted in the past about how bond is depressed when he's not on missions and feels most alive when m gives him orders. when he's not with m[i6] he reacts like it's a breakup, see: his crashout in skyfall where he ghosts everyone and spends his days drinking in the carribean, or how heartbroken he is in ohmss when m doesn't want to send him out.
@halfbaked00q pointed out to me how in qos, everyone keeps saying that bond is avenging vesper, but really the person he is avenging in that movie is m. he's much more animated by the harm done by quantum to m[i6] than vesper. m[i6] means so much more to him, he feels wrecked by the feeling that m[i6] has been violated in such a way, and personally responsible, where he doesn't have the same depth of guilt about not saving vesper.
He thought they would sleep together for a few days and then he might see something of [Vesper] in London. Then would come the inevitable disengagement which would be all the easier because of their positions in the Service. If it was not easy, he could go off on an assignment abroad or, which was also in his mind, he could resign and travel to different parts of the world as he had always wanted. - casino royale, ch. 23
this is perhaps a tenuous reading of this extract, but i find it interesting how he discusses how he'd respond to his breakup with vesper and resignation from mi6 in the same way: detachment from them and then leaving britain.
And it was true that an appointment in the Secret Service was a form of peonage. If you were a woman there wasn’t much of you left for other relationships. It was easier for the men. They had an excuse for fragmentary affairs. For them marriage and children and a home were out of the question if they were to be of any use ‘in the field’ as it was cosily termed. But, for the women, an affair outside the Service automatically made you a ‘security risk’ and in the last analysis you had a choice of resignation from the Service and a normal life, or of perpetual concubinage to your King and Country. - moonraker, ch. 1
this quote is fascinating to me because it makes it clear how, even for men who are afforded more liberties than women in the post-war era, their liberties only go as far as sexual affairs. there isn't a place in their lives for romance, that's taken up by mi6. (particularly if they wanted to be 'of any use', and as being used is bond's primary motivator, it clicks together quite cleanly.)
if we think about how this culture may be transposed into the modern day, i think we can extend the concept of employees of mi6 as concubines out to employees of any gender. you can have relationships outside of the service, but they can't come close to the commitment you have to mi6, and if it does, you have to choose who you want to break up with.
that's all to say i think both q and bond understand their relationship with each other as secondary to their relationship with mi6 (as embodied by m). that is something that can even stabilise their relationship and ensure it lasts, because they share this love, which someone outside 6 would never understand, and wouldn't stand for being prioritised over mi6. (which is also why i think tracy is a good partner for bond, as she understands how much he enjoys his work and supports him with it).
tl;dr: bond and q roleplay in bed pretending m is giving them sexy orders