Meimei's specialty is poetry, chess, and Go. Based on the OP and the scenes with Maomao's syphilitic parent (not 'mother' by the way that Maomao treats her), Lakan's main desire is to spend time with someone who can at least vaguely keep him engaged.
Meimei didn't say that she enjoyed the time either. She implied the only courtesan qualified to entertain Lakan. Intellectually.
One can presume then, that Maomao's other parent was exceptional at Go.
As smart as Maomao is though, experience always wins out. She can't ever seem to outwit Suiren. Can't fool that old nanny one bit!