By Rick Egusquiza

Ellen Degeneres is terrified she may lose partner Portia De Rossi to a man.

The 48-year-old Emmy-winning comic — who swept De Rossi off her feet almost two years ago – is now worried that Portia will leave her for a guy the same way ex-lover Anne Heche did, sources say.

“Ellen’s so in love with Portia I think she’s afraid to be too happy,” a close friend told The ENQUIRER.

“She’s been burned before. Now she’s afraid it’s destined to happen again because Portia’s just so beautiful, and guys naturally come on to her all the time.”

Compounding the problem is that Ellen and Portia, 33, have a group of straight guy friends who kid Portia about “joining their team.”

One offender, according to the friend, is actor Jeremy Piven, who had a role on Ellen’s first sitcom and now stars on HBO’s Entourage. “He’s been friends with Ellen for years,” said the friend. “So Jeremy and his pals drop by Ellen and Portia’s place for card games and drinks.

“Ellen’s probably the funniest woman alive and people just naturally gravitate to her.

“And then she has this smoking-hot girlfriend — who’s also a blast to hang out with. And when their straight guy friends start kidding around about ‘switching sides’ and ‘joining their team,’ Ellen knows it’s all about Portia and not her.

“She can put up with the joking for just so long.”

Read more in this week’s issue of The ENQUIRER.