Oh, I didn't realize that. I guess my translation still kind of makes sense in the context, but I was thinking more like "courage" was what she had in her (instead of penis). Given this new information, "It looks like they're doing it" probably makes more sense.
Misato's finally going through with it...It looks like they're doing it♡
"これ(あれ)絶対入ってるよね" is a meme created by a Japanese mangaka, Miura Jun. This term is used for a pose suggestive of a copulation. See also Nicopedia and pixpedia.