First time some drug pretty much hypnotized him into raping someone but the girl fell in love with him later and he loves her dearly also.
2nd time was his fiancee. The fiancee and him didn't want to marry each other but his fiancee tried to set him up with a sister disciple (although I said set up he was once again drugged but he fought back and defeated the drug this time otherwise that girl wouldve rapped him because of drug + unable to fight back because of drug) so he was also wronged here so he decided to rape the fiancee and pushes away the girl who wanted to have s*x with him that the fiancee set him up with as revenge. He feels guilty later and does his best to save her when they meet again but she wont be a part of his harem.
the MC lives in the modern world and goes hiking with 3 friends, there he finds a purple crystal in a cave then suddenly the cave collapses and he is trapped. His friends pretty much went “poof” no mention of them at all really so its fine to ignore that the author seems to exclude them as they had no roles. Then he digs himself out but when he comes out he appears in a completely different place and slowly finds out it is another world.
He actually digs himself out of his own grave (the grave belongs to someone with the same name as him but is just as 12 year old boy that died) and he noticed his body belongs to that 12 year old boy. So this is pretty much a combination of reincarnation and world travelling, not exactly reincarnation and not exactly travelling to a different world either. Like I said earlier you will learn all this within the first 3 chapters so not much of a spoiler.