On the YouTube channel To Catch a Cheater, this young man put his girlfriend to the test. 

She was at the gym getting in some exercise when the To Catch a Cheater team sent a buff physical trainer in to make some moves on her. He offered to assist her when she tried to use a machine she had never tried out before.

After he tells her that he's a personal trainer willing to give her a few pointers, she agrees to let him continue assisting her for a while. He starts to touch her more frequently; their physical contact is done in a professional and educational context, but it does get pretty friendly and there seems to be some sexual tension.

She doesn't seem eager to set boundaries with him, which frustrates her boyfriend (who's watching on a hidden camera). She declines his request for her phone number when he asks for the chance to go on a date with her, but she does agree to exchange phone numbers for communication about exercise and fitness.

In the end, while the boyfriend didn't love everything he saw in the video, he did agree that she "passed" her test.

The people behind To Catch a Cheater claim that everything shown in their videos is real. That is to say, it's not scripted and the would-be cheaters being tempted are not in on the gag. 

Whether or not you believe that's true is up to you.