@genderbenderbb2
Janjan baribari(じゃんじゃん ばりばり assuming it was written in hiragana) is an expression or rather two expressions used to emphasize each other. The first(じゃんじゃん) means continuously, keeping up the momentum or often, while the second(ばりばり) means with gusto or vigorously, energetically. My feeling is that this way of speaking is a little dated. I can't think of a good English analogue, but basically that girl is saying they're doing it often and as much as they desire. Maybe an actual native English speaker can help think of a good expression in English that would express the same thing?
And what going on ? aren't 2 of them already can feel good except boss ? I mean they try to hide it so she don't feel let behind but this chapter doesn't seem like they hiding and really asking around for real. And then there are the chapter when they suddenly mocking her
can't feel good out of no where too. And now 3 of them can't do it ???