This is a good question. I love both. I love being there when my wife is totally in lust and cock hungry over her BBC. Seeing her cum and squirt over a big dick while I sit back and watch is incredible.
I also love joining in though. For the most part I sit back, but I’ll walk up and “assist” sometimes. I’ll put the vibrator on her clit while she’s getting fucked. Or grab her hips/ass cheeks to help her slam down on her bfs cock. (Not really BF, but it’s her thinking of it that way) I’ll kiss her neck or suck on her titties while she’s cumming.
but I also love her sending me pictures with her throating a big dick, or getting random videos of her riding a BBC on some random couch I don’t recognize. Knowing she’s getting BBC is super exciting