Alyson Hannigan: I'm preparing to send my children to therapy over 'American Pie's' 'band camp' scene

Thirteen years ago, a young Alyson Hannigan gave a whole new, shockingly racy meaning to high school band camp in the first “American Pie” film. But roles have consequences – and now the actress, who is heavily pregnant with her second child, is preparing for the day her offspring asks about those sexually-charged scenes.

“I've already got a trust fund for their therapy,” Hannigan told FOX411’s Pop Tarts column. “I will be talking to a lot of therapists before we have that conversation.”

The now 37-year-old sitcom star said she was particularly hesitant about coming back into the fold and shooting the highly-anticipated “American Reunion” with the original gang.

“I was very, very hesitant, but I met with the writers/directors and they pitched me all their ideas and I thought that sounded really good, so then it was like ‘show me a script’ because I'm not just going to sign on to an idea,” Hannigan continued. “The script was fantastic and it's just gotten better ever since. I think they really captured the essence of the first one which is my favorite… You can expect a lot of raunch, a lot of laughs and a lot of heart.”

Actress Tara Reid returned to revive the role of innocent Vicky, and credits Eugene Levy (who plays Hannigan’s father-in-law in the film) for encouraging her to come back, while co-star Chris Klein admitted that even though all these years had passed, nobody had really grown up.

More On This...

“Unfortunately we digress into our high school selves and all hell breaks lose... But it was wonderful and fun, there was nothing weird about it,” he said. “We've all changed and gone through our 20's and we're all old. Some of us are married, some of us have babies, but we're all still trying to figure out who pooped in the cooler.”

And for those who see the film – he means that, literally.