@Agavadon: I think it's utter naïvete to think she
isn't plotting something at this point. I also think that there's some sort of ulterior motive accompanying that suggestion, especially since she a) shows jealousy whenever Akira gets involved with another female, and b) had ammo conservation as her only reason when she told him to spare Sheryl.
I think she's doing it to loosen
Sheryl up. She can probably tell that Sheryl is trying to loosen Akira up, but the guy is probably 99% hardboiled from the things he's gone through; the remaining 1% is either constantly affected by Alpha (remember when he chose his name at the greater hunter's office) or influenced by her (she's always there, and her "support" also includes guidance on seemingly all things possible). I predict Sheryl will keep intensifying her efforts--or not--and eventually give herself away: if not to Akira, then definitely Alpha and then Akira.
Besides, Akira knows firsthand: flatchests can't compete with big breasts. Sheryl's not just fighting an uphill battle there, she's on a vertical mountainside.