the bible doesnt say anything about position but it does say to be married FIRST.
HOWEVER!!
it also says this "wives/husbands submit to your husbands/wives. love honor cherish one another"
the bible is also agaisnt rape (that thing in deuteronomy is poorly worded but its actually about a pair of lvoers that got caught...not rape)
so...i personally think that..once you're married anything goes from a quick hardon fk to a 2 hour session of bdsm.....but ONLY if you are BOTH in the mood.
also the song of solomon...read that porn book....gods kama satra....they do some...interesting things...in that book lol
finally the bible can have some rather crude jokes. like saint paul whos asexual (non-sexual) wrote corinthans...& in uh..the first one i think...anyway...in one he writes (anti) gay stuff...chapter/verse.....6:9....however did a nonssexual acheive this one? LMAO