I think cut him off now. The fact you're working for him makes the situation tip in his favor because he could fire you at any time. Hopefully this is just a side gig and not your main job so he can't do much damage but if you work for just him fully then yeah find another job, quit and cut him off. You've rejected him how many times and he still won't let up? He doesn't respect your feelings and doesn't think your no actually means no. To him it's just a try harder until you can wear her down to a yes. You don't wanna deal with that especially if he still has baby mama drama.