This immediately made me wonder about my own pairings of choice, which, if we're talking romance/sex, aren't that many, and a) the being able to imagine them just hanging out and b) the broccoli factor. Because it's not lke I shouldn't rather follow Darth Real Life's instructions and get some work done.
So, let's see:
Londo/G'Kar (Babylon 5): pass the "imagine them just hanging out test" with flying colours - one of the many reasons I will defend season 5 to the death is that we see Londo & G'Kar being so comfortable with each other, in an ongoing snark and banter way, sure, but that makes it fun. Starting with the last but one episode of s4, "Rising Star", you get those scenes where they, well, hang out. ( And once Delenn gives them that brilliant "body guard" excuse, they even share bedrooms, but that's another story.)
On the other hand, I'm afraid Vir would have to buy the broccoli. Not just because he would imediately deduce Londo would want some, if Londo did, but because Londo could not go quiet through a supermarket, or pass up the chance to shout indignantly at the owner for withholding broccoli from the great Centauri Republic. Which is a danger Vir would be aware of, and hence he would shop the broccoli in advance, thus preventing Londo from ever entering the shop.
Angel/Darla: broccolis do not apply. Even during the period when Darla is human, she wouldn't touch the stuff. As for domesticity and hanging out: on the other hand, spending 150 plus years together isn't all sex and mind games and eating people. Who do you think Angel picked up a fondness for ballet from? And you know, that trip to Rome where Holtz captures him? It's canon that was about Darla wanting to see paintings. Theirloveissotouristy.
Arvin Sloane/Jack Bristow: are excellent at reading each other, most of the time, and would pass the broccoli test with flying colours, though the broccoli would of course be something either containing a microchip or drenched in Rambaldi juice. Or something. And given Jack manages to be One Of The Straightest Men On TV In Terms Of Vibe, and it's always a big effort to get around that, it's actually far easier to imagine them in non-sexual situations. You know they play chess on a regular basis. Which leads me to...
Jack Bristow/Irina Derevko: Irina knows all about Jack's desire for broccoli, but she had enough of buying those when she was Laura, so she tasks Sark with arranging an explosion in the supermarket instead, which leads to Jack suspecting her, which leads to mind games and sexual tension and then to sex.
Also, when she was Laura she never played chess with Jack because that might have given her away, but she is competely sure if she had done, she'd have beaten him far more often than Arvin did.
Arvin Sloane/Emily Sloane: are the picture of comfortable domesticity. They also have no difficulty passing the broccoli test. The problem is that after having thoughtfully bought the broccoli Emily wanted, and then some, Arvin spots other not so healthy vegetables on the shelf and buys them in secret without telling her.
Bonus 'ship: Tom Zarek/Laura Roslin: would both send Lee shopping instead via clever insinuations.