So the NTR routes are explicit choices?
you can play a ntr lite version from the start, some things are just story related to establish that sex drug.. the rest is avoidable.. however even in a pure NTR route you can avoid stuff especially if you get rid of Lucas when the time comes..
For me personally ive got a few routes to enjoy all the content available
Route 1 - Alpha MC - aka a harem route.. get rid of Lucas and take all the girls for yourself
Route 2 - Alpha Lucas - Help his efforts and have ntr in the household but still going after all the other girls for yourself
Route 3 - Scoundrel Route - Low Morals route, got rid of lucas, claimed everyone, got those possible pregnant etc etc