2 Men & a Weekend Getaway

Margaret • I am very career oriented and I am not planning for a pregnancy anytime soon.
A little bit of back story, a previous, long-term SO and I broke things off this past June due to complications with where we lived. We'll call him *Levi. He had moved to a brand new country across the world to finish his Masters back in April. It was very abrupt and I was never sure if I fully was supportive or all right with his decision. (I mean supportive in his begging for us to stay together or for me to drop my life and studies to move with him- not his pursuing of a dream.) 
After a lot of wine, ice cream, and family support, I've began to healthily move on and start dating again. And after a lot of busts, I met someone who we'll call *Benjamin. 
Ben and I get along really well and he's very understanding of my wanting to move things very slow, easing into something I think could be another long-term. 
I'm not usually someone who meets and dates frequently. I've never been the type to be in long relationship after long relationship- I prioritize my personal growth alone and enjoy my "me time." But I suppose 2015 was the year that defied all other years. 
Now, Ben and I have decided to take the next step and travel away for an extended weekend together. It's been set up for a month or so now and will be happening this following week. 
However, this previous Monday, after not seeing Levi for over 10 months, I got word from him that he was in his parents' town (only a two hour drive from me) for the next 5 weeks and then possibly home for good. He wants to see me. 
After getting word of this my blood felt like ice and my insides felt like they were melting. The sheer shock of it made me want to curl up in a ball and lose it. 
I really enjoy my time with Benjamin and under separate circumstances I think that we would be quite the couple. But, with all these feelings that I felt I repressed for Levi, now flooding back, it's as if I love him as deeply as I did the day that he left and that I'm being deceitful to Ben. 
It isn't fair to Benjamin that I'm feeling this way for Levi, especially after all we've built and after confiding in him that this weekend we've planned is feeling like the right time for us to finally sleep together. (Which isn't fair to promise someone, but I trust him and we talk about everything. I never thought that it would be a question of something to take back.) 
So, my looking for advice lies in: Should I see Levi again? Or should I ignore the fact that he's home and continue to move on with myself and possibly Benjamin? I care about them both very, very much, but it's very hard to let go of someone (Levi) that you once saw spending the rest of your life with when they're practically next door. And it's very hard to forget about everything I've built with someone (Benjamin) who's helped me to remember that I am strong and in no need of another person to make me feel whole. 
Thought?