The slower and deeper relationship is, the better. The girls are people who close with the MC, so they won't touch the MC that quick. that will make them affraid to destroy their current relationship, so teasing the MC and let him do the action first is the best way.
People complains about why the NTR guys always get what they want faster than the MC... The answer is simple because they confess, they attacc, they seduce... and some girls will accept them because what?? Because they tired of waiting for the people they love to make a move that they don't now when they will confess it to them!.. so it's better if the girls accept some random guy who love whatever they are rather than waiting for them to be taken by the th one they love.
sorry for my bad english