I believe in both. My biggest fetish is female orgasm as that is the ultimate sexual expression of pleasing a woman in my mind. I always want that as many times as possible during any encounter whether the context is vanilla sex, lifestyle play (as a Dom or a sub) or Pro/client (yes... It may not be on the paid menu but it sometimes does occur... But only when the Domme decides that is what She wants in that moment). This is literally the only thing I ever beg for from a Domme.

Although I prefer to be directly involved in my partner's orgasm, I am still thrilled by Her taking care of Herself while we play even without my direct involvement (i.e., my touching Her or even holding a toy for Her). Of course I would prefer penetrative sex with my cock, fingers, tongue, etc... But as long as my partner gets off, then I am awesome.

Having said that as the context for my reply, my preference is that sexual contact is not a hard limit when doing BDSM play and I feel everything should be on the menu based on whatever the Dominant partner feels at that moment. However, this is not a hard-core requirement and I can be happy with just fetish & BDSM play if I am being fulfilled in other ways or with what you termed as "straight sex" in a vanilla relationship (keeping in mind I don't believe in exclusive and monogamous relationships in either context so I can have either or both). However, if forced to choose then it would absolutely be fetish & BDSM play.