Theo James' brothers watched him film his sex scene with Shailene Woodley.
The hunky British actor - who is the youngest of five, with two brothers and two sisters - said his male siblings weren't quite prepared for what awaited them when they flew in to see him as he was completing work on 'Divergent'.
He told People magazine: ''My sex scene with Shai was the last of the whole shoot, and my brothers had flown in for a trip to [Las] Vegas. Since filming was delayed, they literally walked off the plane and onto the set to see my getting funky. It was surreal.
''I got made fun of for months.''
The 29-year-old star - who is dating Irish actress Ruth Kearney - has previously joked about how he kept making Shailene ''practise'' their kisses.
He has said: ''I made her practise the kissing scene as much as possible. I'd say, 'Listen, tonight after dinner, can we just go over it again?' ''