Oh good, she's also assuming it would be a woman. For a moment after he asked, Peter had the terrifying thought that Gabe would probably want to be in on something like that, and the even more terrifying thought that Lucy might go for it.

"...But it'd be a threesome. Not...you and someone else." Yep, circling back to that, give him an answer already. And no, he's obviously not jealous.