O'Donnell hasn't said whether or not she will wear an engagement ring, too -- but she might. That's the thing about same-sex engagements, experts say: there are no established norms about who should propose or who gets to wear a ring, since sex-based etiquette rules don't apply.
"Same-sex couples have the freedom to create their own customs, which is what makes it so exciting," Joseph Alexander, founder of same-sex wedding planning firm Gay Ever After, told HuffPost Weddings. "Couples are not bound by the so-called 'typical wedding traditions' where a groom would propose to his bride."
Since legal same-sex marriage is so new in the U.S., fewer engagement rules have developed for couples to follow. So it comes as no surprise that gays and lesbians are taking traditionally heterosexual wedding traditions -- such as formal proposals and ring-wearing -- and reshaping them to form new and individually relevant marriage customs.
"One of the wonderful things about same-sex relationships is that our wedding norms and traditions are developing and unfolding with each new engagement," says Kathryn Hamm, president of GayWeddings.com. "We find that each couple embarks on an engagement or designs a wedding ceremony in ways which best represent them as a couple, rather than according to rules as to how it should go."
Like most heterosexual spouses, gay and lesbian couples often choose to wear engagement and wedding rings. But since many same-sex partners held commitment ceremonies long before gay marriage was made legal in some U.S. states, they often already wear symbolic "wedding" bands.
Michele Kort, co-editor of the forthcoming book of essays "Here Come the Brides!: Reflections on Lesbian Love and Marriage," says the concept of wearing rings isn't foreign to lesbian couples. "Lesbians have long worn matching rings, way before legal gay marriage," so they're more likely to both wear engagement rings, Kort says.
Unlike with heterosexual couples, where -- thanks largely to the diamond industry's advertising machine -- a diamond ring is almost always expected to accompany a marriage proposal, there aren't many norms dictating the "right kind" of engagement ring in same-sex relationships. "Most couples, at least those with whom we work, really seem to focus on creating meaningful rings and true symbols of their relationships," says Hamm.
"I think lesbians would be more flexible than just the standard diamond," Kort says. "I think [they] would tend to look for symbolic images or designs, perhaps."
Hamm wonders if same-sex couples' tendency to define their own wedding rules will spill over into mainstream heterosexual wedding planning. She asks: "[Has] the LGBT community's openness to taking the best of wedding rituals and re-purposing them for our own commitment and marriage ceremonies ... actually impacted, shaped and changed the way that heterosexual couples are now approaching their engagements, wedding rituals and ring wearing?" Given the recent trend of straight couples bucking traditional wedding etiquette rules (think the rise of DIY and "indie"-style weddings), Hamm might not be so far off.
Still, despite the flexibility to choose the best ring to represent a couple's relationship -- and despite the heteronormativity of most diamond advertising -- a giant rock is still mandatory for some gay and lesbian couples.
"Generally speaking, there are fewer expectations in place, but this is changing," Hamm says. "There are plenty of gay men and lesbians who have wandered ... into a jewelry store hoping to purchase the perfect stunning ring for their beloved one."
Alexander says that ring expectations differ from couple to couple: "Some may choose exquisite diamond rings, while some may opt for a simple, platinum band. I have even seen two women that chose to have rings tattooed around their finger instead of wearing traditional jewelry."
When it comes to who should propose, experts say it all depends on the pair: "It's probably the person who's the most eager and the least afraid of rejection!" Kort told HuffPost Weddings. "But I wonder, in couples when one person is more financially dependent on the other, if it's the person with the most finances that proposes?"
In O'Donnell and Rounds' case, Kort says, "I'd guess that Rosie's wealth and status -- and, probably, her more dominant personality -- might suggest that she would propose."
"I've seen many cases in same-sex relationships where there is a more dominant person in the relationship, but I have worked with heterosexual couples where the woman proposed to the man," Alexander adds. "Love is love and no one has to abide by typical customs."