I'm not saying this is happening in this game, but I've notice alot of VN's let the "slow build" relationship go on sometimes a little too long. There is a sweet spot that a dev can find with building sexual tension between scenes and alot of the times I've noticed slow build for the sake of it, not to create better tension. The stuff with Nicky is pretty hot, but is kinda getting silly
TLDR when build goes on for too long it gets boring. When there is no tension building at all, it is also boring.
Find the center!