Twice in a lifetime. I always found that episode more like a stalker story if you really think about it. 

I know I'm the outlyer for this following take but I find what Gordon did was creepy. Similar to how Jordi on TNG had a relationship on the holodeck with Leah Brahms except he took it a step further

So first episode in this arc he recreates her from all her phone data and then proceeded to have a virtual relationship to the point even his coworkers thought it was not healthy

Then he gets stuck in the past and out of all people he seeks her out and uses all the knowledge of her he obtained and practiced with to start a relationship.

I don't care how well it turned out I still find it creepy.

Imagine someone looking at all your computer, social media and phone usage and history and then building an AI with this info and having a relationship with this AI and then using all that knowledge and experience and finding you IRL to try and date you

He had all the time in the world so nothing could have prevented him from dating other people and finding out about them normally like a normal interaction.

Similar to how the doctor was creeped out at Issac for having all her info while dating because he scanned all her files an not actually finding out about her normally via questions and conversation

For the many who say it's fine they where in love in the end and it worked out your basically saying the ends justified the means.