from where I'm sitting if you're not a sadomasochist then you're missing out on the great fun we're having.

If it's possible for non-sadomasochists to fail to appreciate the fun sadomasochists have, surely it's also possible for sadomasochists to fail to appreciate the fun some other people have; unless you've somehow ruled out the possibility that you might be doing that, I don't see how you can be justified in assuming that others are missing out.

For instance, consider the following hypothesis (which, for the record, I think is extremely unlikely to be right): that what distinguishes sadomasochists isn't the ability to have a kind of fun that non-sadomasochists don't get, but the inability to get so much fun from "ordinary" sex without sadomasochistic accoutrements. If anything like that were true, then there'd be plenty of non-sadomasochists having just as much fun as the sadomasochists; do you know that no such thing is true?