Disclaimer: I’m aromantic, so I’m using “significant other” to generically mean “the person/people in my life who I would expect to show me the highest level of support.” Also, I’m not the best marketer, but I’m great at having strife-free relationships, so my perspective might not be too helpful if maximizing profits is your bigger goal.
Overall, I don’t want or expect a seller/customer relationship with my significant others. My fans should pay me; my significant others should be there for me in other ways (like listening to me complain about my Patreon, lol XD). They can pledge, but I don’t want them to feel they owe it to me, and I wouldn’t want their pledge status to affect our relationship.
I’ve never asked a significant other to pledge to me. My two closest people did voluntarily, over time - one on Patreon and one elsewhere because they didn’t want to pledge on Patreon. A key reason they pledged was because they were also legitimate fans of the work I was creating, so they saw all the same content and communications I sent to any of my other readers, including my explanations of why Patreon is important to me.
Before they pledged, I occasionally shared limited Patreon content with them whenever I was excited to show them something. I only gave what I genuinely wanted to give, with no strings attached or expectations of reciprocation.
There are other people in my life who are important to me but who aren’t involved in my creative endeavors and don’t pledge to my Patreon, and I’m fine with that too. If they don’t consume my work, I don’t expect them to pledge.
If I were to hypothetically imagine being on the flip side, I’d feel uncomfortable if someone I was dating asked or expected me to subscribe to a paid service of theirs. It’d feel like an obligation. Whether I’d feel inclined to subscribe on my own depends entirely on our relationship and whether I was also a consumer of their work.