Tazune is clearly reaching out to Doumyou with the intent to hook up. Apparently he feels entitled to do so because he's not getting enough nookie from his distressed pregnant wife.
Doumyou clearly is a selfish twat because not only did she ask her married and pregnant friend if she could come over to her gatdamn house to tell her gatdamn husband that she had feelings for him, she saw him treat his wife like dirt and STILL had the gall to spit mean at her at work.
Tazune and Doumyou DESERVE EACH OTHER, they go together like a dumpster and a nasty grease fire, and I hope that their cheating is what finally drives Midori to GET OUT.
And we all know it'll be to Maki.