I find it somewhat odd that your boy is planning out and requesting sex positions for first-time fucking. I’ve never been in that situation before and I don’t know whether or not you’re a virgin, but I think it to be quite unfair of him to put that pressure on you. You don’t know one another intimately, you’re new to intimacy altogether - best not to go into it with any preconceived notions. Things unfold and happen in the moment. Let it be :3
But if you do end up straddling your boy some day and find yourself facing these insecurities, it’s natural to feel kind of weird about it - because sex is weird. It’s primal and full of lust and love and all sorts of things no one can describe or attempt to explain. One minute you’re really into it and the next you’re wondering whether or not your boobs and fat rolls are flopping around too much, but then you get distracted by more pleasant things. Like how brilliant sex is.
Try not to stand in your own way. If it feels right with this boy, then let everything happen naturally. It may all make sense or it may be confusing, but it’s never boring.
I’ve not talked much about sex on here much, feels naughty <3