Not all omegaverse had the same rules since its main plot point is the pregnancy and heat mechanics so sub-rules are usually wtv the author wants lol
Marking is just marking, take it as a behavior, an action it doesn't represent affection. Everyone who is capable sucking your skin and left a hickey can leave a hickey without they have affection towards you what I can use as example for this case.
Marking also not bonding. Marking can be done just with pheromones or oj different world building, it can be done through semen or light bite.
Even the most binding marking which is bonding through marking bite (usually happened during mating when the alpha and omega simultaneously having rut and heat together) can be done without any affection.
So basically if the seme is an asshole playboy like the one we see here, then welp. Marking is just marking lawl. No meaning about it. He didn't give it too much thought.
As for the one you mentioned about adverse rejection towards alpha usually happened after the marking bite-bonding type.
I don’t get it, am I the only one confused about this omegaverse? Shouldn’t be the one who marked the omega feel jealousy and possessiveness towards anyone who approaches their omega? Or shouldn’t be the omega feel adverse rejection towards another alpha if it isn’t his/her alpha who touched them? Or this just another type of omegaverse?