If Sensei is fucking her, Maki struggles to say what she means, but more or less is trying to say she likes likes him:
Then she (accidentally?) mentions she's had a lot of different dicks in her, and seems to run away embarrassed.
Although, in retrospect, her dry spell seems to correlate to Makoto getting laid, and since Makoto hasn't had sex in months, Maki probably can now:
Seriously though, Maki has some Chika level of denial at times. How she hasn't figured out Sensei is fucking her daughter is... beyond me.