Wait ... who's the dumb one again? I thought Maa-Kun was the dumb one because even though he clearly has some feelings for her he keeps pretending his teenage libido does not notice. Or was it Megumi who was the dumb one for not confessing already.
Honestly, it's been more one-sided in her feelings for him and his ambivalence/ignorance of his developing feelings for her. Until he admits he feels something for her (even if he just admits he feels lust) we'll be stuck in this loop. Well, that is unless she confesses properly. If she did he wouldn't be able to ignore his libido feelings anymore.