@beperov
When Firo was smothering Rabi, her dialogue alludes to two things:
1)
An individual’s body learns with experience. If Rabi stays alongside Firo in future missions, he might be able to gain experience (EXP) more efficiently. His body can become more toned, with her pampering. At least, that is what Firo believes. She phrases her statement to Rabi suggestively, as per her character trait. Also, remember the monster-doping that happened in the previous chapter; Firo could probably do more of that.
2)
Firo is mirroring Connie’s statement from when Connie hugged Rabi. Rabi can depend on Firo in his times of need, forever. Even if he turns dumb. Firo keeps looking down on shrimpy Rabi...
Hopefully that clears things up.