If all she could do this night was get to watch, she'd totally be okay with that because that's how turned on she was. So turned on that even though they were essentially crushing her legs, she totally didn't care. Kirk's tongue in his ass and then watching Tony wrap his mouth around Kirk's cock, she was fascinated, and if she could have wiggled, she would have.
Because she could, she slid one hand into Tony's hair, like she would have if he'd been doing that to her. Her other hand sought out to touch them both, lightly stroking Tony's cock, or Kirk's stomach or whatever else she could touch.
Sometimes her lips pressed against his back, nipping and kissing here and there where she could reach.