So let's give this a shot. We're a couple, so answers will blend M & F perspectives.
1. Favorite sex position(s)? Lots. Face to face with her calves over my shoulders; great for either vaginal or anal. "Standard" doggie (knees) not so much, but standing doggie (e.g., bent over the hood of a car); usually easier for anal than vaginal. Spooning - very nice for anal.
2. Age you lost your virginity? College - together.
3. Do you like to role play? And if so, favorite role(s)? We don't get into role play. Feels too fake for both of us. We do some things that might "look" like role play - like the occasional BDSM Dom/sub kind of thing, but that's not role "play" - we are each playing out our real natures, but with exceptional intensity and drama. The closest thing to role play we've done would probably be a couple of "Clothed Female nude male" events - sort of a Femdom / male sub kind of thing. In that case, neither of us were playing to true nature, so maybe a form of role play.
4. Dominant or submissive? I'm Dom, she's sub. Just our natures. That's not to say we can't play otherwise.
5. Swallow or not? She definitely swallows.
6. Bra (or penis) size? She's modestly endowed, neither buxom nor a member of the "itty bitty titty committee". I'm on the large end of the scale; not the largEST, but a couple of inches larger than anything I've ever heard called "average".
7. Multiple partners? And if so, how many? We've never been bed hoppers, but over time we've been involved with a number of others. Mostly her with me behind a camera, so she's had more partners than me, both men and women.
8. Fetishes? There's a tendency to call any sexual practice out of the mainstream a "fetish", which isn't right. But using it in that incorrect way - yes - perhaps many fetishes. We are open to a wide range of sexual adventurism. Clinically, a fetish is really something onto which "normal" arousal is displaced and is needed for someone to achieve sexual satisfaction above and beyond or maybe completely instead of "normal" sexual relations. For example, a guy who can only get off on bare feet - a girl who has to have her hair pulled - etc. In that more clinical sense - no.
9. Height/weight? She's average, I'm big.
10. Favorite fantasy? I am vastly more aroused by reality than fantasy, so rather than fantasize, my mind goes to actual experiences, relived in memory, rather than fantasizing. When I DO drift into fantasy, it is not about things that can't be, but more in the nature of planning and calculating how to make an arousing/exciting idea happen. There's always a few of these on the drawing board, but if they don't develop into plans for real experiences, they tend to lose their appeal. An example: I would like to set Mrs. Pix up with several heavily endowed guys at once; not necessarily a gang bang, but a scene in which she can be penetrated vaginally, anally, and orally all at the same time. That seems achievable, but has not yet happened, and so remains a long-standing hot fantasy.