You will be relieved to know you're right. Grayson lied to scare Chase into going to orgy parties with him. Bc Chase used to let his pheromones build up until it erupts. After the whole "Alex" incident, Chase has then "obediently" follow Grayson to those parties bc he's scared of what might happen if he blacks out again.
Soooo...... He's sleeping around and releases his pheromones in those parties? I mean yeah, he has Joshua now, but damn... Grayson is cruel... Idk how he'll behave when he'll be (spoiler) with the firefighter from Kiss me, Liar. Does anyone knowd about it? I couldn't read the novel(s), because the english translation literally hurt to read...
No, even at the parties, he doesn't sleep with ppl. He takes drugs that help him release his pheromones. Chase was very sex adverse. He only ever wanted to have sex with someone he likes, not with strangers.
In Kiss Me, Liar. The author took the comedic route. Whenever I reread Kiss me if you can, I hate Grayson's guts. But reading him in kiss me liar, I'm more sympathetic to him.

the part with the bestiality made me so uncomfy holy shit but i also agree with the theory that it was a lie made up by grayson to mess with chase and he ended up sleeping w joshua that night. STILL, THATS SO MESSED UP