Sorry, but it's not as bad as it looks. Well.... It's definitely Erotica. But that's mostly in the characters' imaginations.
Harem only applies here in that the three female leads are in a low-key war against each other to score the MC. Fortunately, they're all pretty amicable towards each other. Really, it's almost like a trio of besties all trying to one-up each other. They tease and razz each other mercilessly, but it's all friendly banter.
What's more, MC is fully aware of what's happening. That said, he prefers one, but the other two have been growing on him, so it's looking more and more like his eventual choice is gonna be a difficult one. Though with the connections he's been making, that may not be an issue.
The sexual violence tag is all due to a recently deceased villain. Fortunately, none of our good girls wind up being raped, but it's a close thing. And his ending is quite cathartic to see.
MC himself is a goddamned billy-bad-ass. He's not widely known, though, because he dropped out of being an active adventurer and went on to work in the guild. But if he chose to do so? Even at forty years old, he could become the world's strongest adventurer. The sheer weight of his intent can make even wyverns freak out. Even his looks have not lost their edge. At one point, some beef-cake photos of him got published and they had to deal with a slew of middle-age, single, noble women coming out of the woodwork to try and bag him. Fortunately, they're mostly dealt with off-screen.
The female leads each have their own reasons for pursuing him, but they all pretty much center around the MC being the world's biggest Giga-Chad. The only reason why he isn't married already is because he devoted himself too much to his work, and the few he did date were definitely not his type.