With three thousand beauties in his harem, Emperor could be considered quite devoted compared to ancient monarchs. But if you think about it from another angle, Emperor is an immortal who has lived for who knows how many years; the number of people who have fallen victim to his charms over such a long time must be substantial.
After listening to Emperor recount his messed-up romantic history, everyone had only one thought: this old geezer really isn't a good person, being even more of a scumbag than a typical deadbeat.
Setting aside what happened to those poor souls, even his so-called brothers are nowhere to be found now, and Old Man Yellow hasn't bothered to go out and look for them in all these years.
Then again, considering Old Man Yellow's educational standards are even more unhinged than those of Great God Blue Dream next door, it's possible that if he did, it would truly result in a fractured empire and a bunch of old geezers fighting over gold coins.
Feeling that his image had hit rock bottom, Emperor tried to salvage the situation by pointing at the primarchs:
"Don't imagine me as such a villain, alright? I never forced them; it was a perfectly legitimate, free-spirited romance. Every time they passed away, I would grieve for quite a while, and that is how you all eventually came to be."
That might fool others, but it couldn't fool himself. Hogg knew this bastard was playing the emotional card again. If not for his own intrusion, Emperor would likely view the primarchs as nothing more than convenient tools.
To say there was no affection wouldn't be entirely true, but Old Man Yellow was extremely biased, with eyes only for his Wolf-Herder God. If he had been even slightly more human, Mortarion