My guess would be the optional cheek kiss that the woman with the plant she wants the LI and MC to kiss under, if you choose to the LIs tend to brush it off or get flustered, afterwards if you choose the romance option they acknowledge they liked it and if you choose the friend option they don't talk about it after.
Unexpected cheek kisses aren't everyone's cup of tea, which is absolutely fair enough, if it helps any it's a cheek kiss which you can avoid (you get the romance option either way!)