The girls' legs. Rei ignores everything around her.
Girl (OFF):“Suzuhara’s got a dirty look in his eyes!”
Other Girl (OFF):“Ikari-kuuuun”
(Other ad libs)
Girls making noise at the poolside.:“Ikari-kuuun! and similar lines.”
Reichu: “Do something about your horny friend!!!“
thewayneiac: Shinji seems to be really popular with the girls. Too bad he can't figure it out.
Sailor Star Dust: Heh. Shinji's oblivious or clueless on how to deal with his fan-club. (At least Asuka has no qualms with ignoring her own fans when she arrives.) I always smirk at the "Ikari-kun~~" line.
NemZ: Or perhaps they're calling out to him because he's staring in their direction? In any case, his complete lack of response should probably be rather off-putting to any of the 'fanclub' paying attention who haven't already started mentally rewritting him as a tragic prince.
thewayneiac: I think we're supposed to contrast it to their "yuck" response to Toji and the others watching them.