You don't have to indulge in pre-marital sex to determine sexual compatibility with your partner.
Sex is something that many would rather leave till they are married.
People make decisions as this all the time; whether due to absolute virginity, or in some cases, just a decision to abstain from sex till they get married.
For people like this, one of the most difficult things would be the determination of sexual compatibility with their partners.
Obviously, it's OK to not have sex before marriage, but it's not cool to not talk or discuss it before then.
The story has once been shared of a bride who was asked by her new husband for anal sex on the very night of their wedding or sometime thereabouts.
This particular couple had both abstained from sex till that wedding night, and when the time came to consummate their union, it occurred that they both had totally different ideas of what sex was meant to be like.
Apparently, the couple in question must surely not have had proper talk about their sexual preferences and towing such line in a sexless relationship could be the deadliest recipe for disaster.
Deciding to not have sex before marriage is not a bad thing, and if that is what you want with your partner, it's absolutely fine.
But choosing not to ascertain the sexual compatibility between you and your partner before taking such a huge leap as marriage is not advisable. And to determine the sexual common grounds between yourself and your partner without actually doing it, all you need is communication.
Unabashed, unrestricted, honest-to-God conversations. Large doses of it.
You need to ask all the questions imaginable, cover all the possible bases.
It is never enough to limit your talks to banks statements, number of kids, etc, only to relegate sexual compatibility to a place of nothingness. It does not work that way.
Since you will not actually be engaging in the sex, it is only logical to ask and have honest conversations about what that partner sees sex as, and what teases and pleases them, what they can do, what they can't, and what they can't do without.
You need to listen to your partner's opinions on accepting and giving sexual pleasure, and gauge whether you can live up to that expectation or not.
You'll need to voice out what you find impossible and ridiculous. You also have to be open to bending a bit here, being accommodating a bit there till you both reach a common ground on the subject.
And this applies to both partners.
If you are both comfortable with it, these conversations could be during couples pre-marriage counselling, where you have someone 'supervising the negotiations.'
Whichever way you want it though, let it be known that sexual compatibility can be deciphered to a large extent without actually having sex if you both will just communicate right.