Originally Posted by Tonberry
The first one would probably hurt my feelings more, but physical attraction is something you're aware of early on, I assumed by sexual compatibility you meant sharing fantasies and the like. Which in polyamorous relationships isn't as much as a big deal if you don't share 100% of the other's kinks, as they can find someone else for the ones that you're not into.
Actually it can be a really big deal. For example, what if you meet someone who you get along fabulously with, start dating, become extremely close emotionally and find out that the person you are dating is extremely into bondage. As in "will turn down sex if it isn't mixed with bondage" into bondage. Unfortunately something like that will mean that(unless you also are into bondage) you will not have a sexual relationship. On the other hand if you had sex early on it would become quite clear that you were dealing with "super bondage person" and part ways without painfully severing a strong emotional connection.