She currently plays tough detective Erin Lindsay on Chicago P.D.
, but Sophia Bush
's first big-screen role wasn't so parent-friendly.
"The first time [we watched her] was in Van Wilder,
" Bush's mom, Maureen, tells PEOPLE. "Kissing Ryan Reynolds
, her butt in the air … we were like 'Whoa!'"
While mom calls it "awesome" but a "shock," the actress, 31, recalls the movie-watching experience with her parents as "super, super awkward."
Though Bush can't catch her hit NBC show with her parents these days (she clocks in 16-hour work days on set in Chicago), Bush's mom and dad are still her biggest fans.
"We wouldn't miss it," says Maureen, 62. "We watch it live, even with the commercials. It's my girl!"
And just like any other mom, she still worries "every time I know she's flying or traveling or in the snow," but when it comes to the actress's career, she's always been fully on board.
"They've always been there and [now] they're great friends to me," says Sophia. "I don't think that works when you're 15, but when you're 30 it's amazing."
For more on how stars celebrate their special bond with their moms, pick up this week's issue of PEOPLE, on newsstands now.