I feel exactly the same.
And I wonder, maybe Rogi killed Reika's parent[s] and adopted her after this? He is so scared to loose her, he pampers her and do everything to make her happy - IMO it looks like he believes, that she will leave his side if she'll know the truth. Like she'll have every right to do this.
Omg I won't be able to handle it if he killed her parents...... ╥﹏╥
However I don't think it is in this mangaka's style to goo so far into tragedy. Even the Seme's past is fucked up (sexually abused by his father) but the way she touched on the subject was lightly, so I don't think she'll tread so far into making Rogi doing something that unforgivable
I'm kind of conflicted for saying this but I don't hate Rogi as much as I thought I would. He did blackmailed/forced Tatsuyuki into having sex with him but Tatsuyuki himself agreed to it and they treated the sex in a very Yakuza-like fashion that instead of "rape" it just seems like a typical deal in the shady world they live in.
Tatsuyuki was angered (which is why he almost killed Rogi) but in the extra we see that they're back to the blatant yakuza The Boss-The Subordinate relationship when Rogi was trying to find his daughter. I still don't forgive Rogi for his past actions but I do NOT hate him as a character. Shall be looking forward to his spin-off. Hoping he gets a better ending.