Sure the synopsis sounds weird, its true that the MC is a huge weirdo, indeed the title is kind of a turn-off. But this manga is a solid 8/10 so far, don't let the 6 star rating fool you. Give it a try, keep reading and then rate it, reading a chapter or 2 is not enough to accurately rate something (99 per cent of the time).
Mc is an insecure weirdo but great guy who wants the best for his wife and also her first time ( Why are so many people creeped out about that i have no clue ). His motives change quickly once he goes back in the past and he start to become a simp who does anything to protect his future wife(?).
Edit: I've just realised that ⅓ of the ratings are 1 star. Just from that i can almost tell you certainly that a ⅓ of everyone who has rated this manga, haven't even read it or read the first couple of chapters and nothing more. Unfortunately there's no way to justify your rating on MD so the 90~ people who've rated this as appalling
can't explain to everyone why they did so.
TL;DR: Dont let the title, rating and synopsis fool you just distrust all the rating on MD because emotions are involved not even mine. Rant aside great story so far imo.