"Should we just kill him and bury his body?" Chris Evans is stage whispering into the impassive blinking light of my digital recorder.

"Chris!" shouts his mother, her tone a familiar-to-anyone-with-a-mother mix of coddling and concern. "Don't say that! What if something happened?"

We're at Evans' apartment, an expansive but not overly tricked-out bachelor-pad-ish loft in a semi-industrial nowheresville part of Boston, hard by Chinatown, near an area sometimes called the Combat Zone. Evans has a fuzzy, floppy, slept-in-his-clothes aspect that'd be nearly unrecognizable if you knew him only by the upright, spit-polished bearing of the onscreen hero. His dog, East, a sweet and slobbery American bulldog, is spread out on a couch in front of the TV. The shelves of his fridge are neatly stacked with much of the world's supply of Bud Light in cans and little else.

On the counter sit a few buckets of muscle-making whey-protein powder that belong to Evans' roommate, Zach Jarvis, an old pal who sometimes tags along on set as a paid "assistant" and a personal trainer who bulked Evans up for his role as the super-ripped patriot in last summer's blockbuster Captain America: The First Avenger. A giant clock on the exposed-brick wall says it's early evening, but Evans operates on his own sense of time. Between gigs, his schedule's all his, which usually translates into long stretches of alone time during the day and longer social nights for the 30-year-old.

"I could just make this . . . disappear," says Josh Peck, another old pal and occasional on-set assistant, in a deadpan mumble, poking at the voice recorder I'd left on the table while I was in the bathroom.

Evans' mom, Lisa, now speaks directly into the microphone: "Don't listen to them—I'm trying to get them not to say these things!"

But not saying things isn't in the Evans DNA. They're an infectiously gregarious clan. Irish-Italians, proud Bostoners, close-knit, and innately theatrical. "We all act, we sing," Evans says. "It was like the fucking von Trapps." Mom was a dancer and now runs a children's theater. First-born Carly directed the family puppet shows and studied theater at NYU. Younger brother Scott has parts on One Life to Live and Law & Order under his belt and lives in Los Angeles full-time—something Evans stopped doing several years back. Rounding out the circle are baby sister Shanna and a pair of "strays" the family brought into their Sudbury, Massachusetts, home: Josh, who went from mowing the lawn to moving in when his folks relocated during his senior year in high school; and Demery, who was Evans' roommate until recently.

"Our house was like a hotel," Evans says. "It was a loony-tunes household. If you got arrested in high school, everyone knew: 'Call Mrs. Evans, she'll bail you out.'"

Growing up, they had a special floor put in the basement where all the kids practiced tap-dancing. The party-ready rec room also had a Ping-Pong table and a separate entrance. This was the house kids in the neighborhood wanted to hang at, and this was the kind of family you wanted to be adopted by. Spend an afternoon listening to them dish old dirt and talk over each other and it's easy to see why. Now they're worried they've said too much, laid bare the tender soul of the actor behind the star-spangled superhero outfit, so there's talk of offing the interviewer. I can hear all this from the bathroom, which, of course, is the point of a good stage whisper.

To be sure, no one's said too much, and the more you're brought into the embrace of this boisterous, funny, shit-slinging, demonstrably loving extended family, the more likable and enviable the whole dynamic is.

Sample exchange from today's lunch of baked ziti at a family-style Italian restaurant:

Mom: When he was a kid, he asked me, 'Mom, will I ever think farting isn't funny?'

Chris: You're throwing me under the bus, Ma! Thank you.

Mom: Well, if a dog farts you still find it funny.

Then, back at the apartment, where Mrs. Evans tries to give me good-natured dirt on her son without freaking him out:

Mom: You always tell me when you think a girl is attractive. You'll call me up so excited. Is that okay to say?

Chris: Nothing wrong with that.

Mom: And can I say all the girls you've brought to the house have been very sweet and wonderful? Of course, those are the ones that make it to the house. It's been a long time, hasn't it?

Chris: Looooong time.

Mom: The last one at our house? Was it six years ago?

Chris: No names, Ma!

Mom: But she knocked it out of the park.

Chris: She got drunk and puked at Auntie Pam's house! And she puked on the way home and she puked at our place.

Mom: And that's when I fell in love with her. Because she was real.