Most of the omegaverse I've read has the omega bound for life with any alpha that bites them during heat and can never sleep with anyone else without a ton of pain, but the alpha has no effects what so ever and can go around and sleep with as many omegas as possible. One of the reasons I really dislike most omegaverse. One bite during rape and the omegas future relationships are basically done for, but the alpha has 0 worries
If an omega is bitten the only one affected is the omega, he cannot have sex with other people that is not his alpha... but the alpha still is affected by other omegas pheromones, that is why we can see alphas having more than one omega all of the bitten...
Is when they are Soul-bound when the alpha only reacts to his omega pheromones, so is safe for other omegas have their heat in front of that alpha!!!
I have seen stories about alphas having more that one omega but I thought that if an alpha met his/her "mate" and marked/bit him/her, then he can only be affected by his mate and no one else? That's why they're always talking about "marking" or "finding your mate". Aren't Misaki them mates? That's what they said in the first few chapters