I don't wanna share

my step-dad sits me down for a serious conversation and tells me he plans to propose to his gf. im obviously furious because I didn't even know he was dating anyone.. this is too much. later on, I come back to talk after ive sorted my feelings. I realize now that my biggest issue is that im jealous. I don't want to share you and I think I can satisfy you, step-daddy.. can I show you.