All the relationships on OUAT have a high creep factor; even ones that started off well.
Look at Snowing—it began as an epic love story and now they attached to the point that they are willing to die for each other (and sometimes Regina) leaving their two children behind!
Nevermore is right that it’s largely thanks to Bobby’s portrayal that Rumbelle doesn’t have a high creep factor. If you read the initial draft of Skin Deep there’s much more to the opening war cabinet scene–interactions between Rumple and Belle that show he was drawn to her and took her because he found her desirable, not simply to upset Moe, as it comes across on screen thanks to some editing.
(and this is, of course, to say nothing of the fact that Rumbelle has taken quite the emotional beating over the past few seasons with a real ugliness coming to bear in the way Rumple AND Belle both attempt to negotiate each other’s identities to fit into some sort of more acceptable mold)
Love on this show is petty, demanding, childish, stalkery, creepy, obsessive, and sacrificial to the point of self annihilation and internal/identity annihilation.