Jennifer Aniston too high-maintenance for Justin Theroux?

Jennifer Aniston has been alienating her boyfriend!

Sources say Justin Theroux has started to see how high-maintenance the actress can be.

“Justin really can’t believe how vain Jennifer is. He will want to go to a restaurant and Jen will say that the food’s too fattening or that she can’t stay up late because she’s getting up at 6 a.m. to go to a workout,” a source told in Touch Weekly magazine.

“Justin has been saying that their love life is more like a science experiment and he’s really fed up with it. It’s hard to deal with her neurotic side.

“And he’s starting to feel like Jen is scheduling all of his time up so that he won’t be able to see his friends.

“Jen also thinks it’s unhealthy that he still talks to his ex, Heidi Bivens.

“If Jen doesn’t loosen up the reigns on their relationship, they may end up spending time apart.”