I haven't read kiss me, liar either and I feel like I missed absolutely nothing. Don't even bother with the other stories cause they're absolute dog shit, I tried getting through kiss the bride and genuinely could not and my standards are extremely low. This feels more like a stand alone story thet might just share the same universe but thats all.
Koss me liar is honestly useless in this story. The only plot point that relates to here is the omega in kiss me liar (forgot the name) gets help from the omega here for his child or whatever. Nothing really important. And just seeing the kiss me liar couple from time to time
"Kiss the bride", although same author, doesn't belong to that universe, same goes for "Roses and Champagne".
So far only "Kiss me liar" and "Kiss me if you can" have an manhwa adaption.
There are 6 more novels/webnovel that belong to that universe: "Lick me up if you can", "Eat me up if you can", "Desire me if you can", "Kiss the stranger", "Kiss the scumbag" and "Kiss my grits". And there are more titles planned.
You only miss some background informations, some characters are in both stories and it takes place around the same time, but if you don't know "Kiss me liar" you won't be aware of it.
The bigger problem is when the manhwa adaption leaves out things of the novel.
For example you will stumble over "gammas", the comments were full of questions what that is. In the novel is was explained earlier.
I think kiss me liar works better if you read the future novels that willl tie into that one concerning Pittman’s blood line. This one is more so on the Millers Family but it will all wrap around into the novel universe that Zig is making. KISS me Liar and KISS me If you can only briefly have the characters crosss paths. So technically you can skip it.
wanted to start this one but i was told that kiss me liar is a related story -- but i didn't like the art so i didn't want to read that