It is obvious that she will lose.
The only character that is going to lose is Aki. At this point it's obvious that he fell for Makoto, but while she isn't beneath fooling around with him when her husband is out of commission, she has her borders and she would never leave her cozy life for a struggling mangaka.
Masami isn't serious about him either, she liked him in college, but when an opportunity appeared she entered a relationship with someone else and probably that's gonna be the role of Takumi in this series, while she decided she doesn't want a messy relationship with him it will probably happen anyway after she fails with Aki-senapi again this time.
The rivalry between Makoto and Masami is a game in which Aki can only lose: Masami wants his virginity, Makoto will guard it from her, but will not take it for herself.
Ultimately I still believe Aki and Makoto will have sex once in that empty apartment before they'll have to move out and then go their separate ways, but it will just leave Aki empty inside and Makoto more prone to cheat in the future.