The part that bothers me the most is that clearly that scene is to be taken as smut for us to enjoy. I'd actually be less bothered if it wasn't meant to be sexy (i.e. the uke wasnt able to get hard), because that would have been realistic still made some sense in the story. While still unecessary, I can see how this could contribute to the plot.
Also, it was just uncomfortable how the uke was on one hand acting like he's in a lot of pain (which makes sense) but also coming over and over. Like he's getting a hole punched in his gut, I'm surprised he didn't pass out sooner. In general, this scene was very uncomfortably violent with the added dynamic of their parent/child relationship.
I really liked this chapter! The previous ones felt a little rushed, and this did a good job of dialing it back and explaining the context of their relationship. I feel their issues were due to a lack of communication and different expectations. Clearly they both loved each other, but they also had a power imbalance which enabled the rich guy to do whatever he wanted. I don't think it was malicious, but he lacked consideration for his partner (hence their current break-up)
On rereading, I think the guy who raised the mermaid (and named the MC) is also the company owners biological father? Cause the guy was a sex worker, and it's implied both that the owner (glasses guy) was an illegitimate child and that he looks like "the man who was nice to women". If true, it's cool how it ties together.
I love how the second volume is just wholesome without any stupid relationship drama