Dating Advice: Should You Hook Up With An Ex?

So I should probably warn you right off the bat that this isn't going to be a funny post, and it doesn't even really have a dramatic plot-line to it. This is a story about having been in love once, and now being uncertain about what level of contact with an ex is okay (and will allow me to survive without breaking my heart again). This post is about Mega Love.

We met in January 2004. 

We were exclusive almost right away.

We broke up in October 2009. (That's just under 6 years for those that want to skip the math)

We broke up because I couldn't take the long distance any longer (and may have just been unhappy with the relationship in general) and he wasn't 100% sure about marriage yet.

I've since realized it's likely I'll never get married and/or have babies (it's not really what I want out of life)

I don't really know his thoughts or feelings on the matter at current.

He wanted to be friends and have contact.

I did not (nor did I think I could handle it).

We essentially broke up over the phone. 

During Christmas break 2009, I went shopping in seattle.

We met up for an hour or so and had some much needed goodbye kisses and hugs.

I was in a good place. I still thought we might get back together. So did he.

In January he came up to Vancouver for work for a weekend. We met up. We had closure sex. I only spent one night at the hotel wit him because it was hard to sleep (I have restless leg syndrome and sleeping is a real issue for me). The next night we just had sex and then I split. (I don't think he was too happy about that).

For me, the closure weekend really was closure. I no longer wanted to get back together. I was happy we had split. Things were good. I have no idea how he felt about it. I told him I would call after my exams in April.

Just before I leave for my friend's Vegas stagette, he emails to say he's coming up and do I want to hang out. I'll be away at the stagette so I can't (whew for having an honest out).

When I return home and after writing my final final I send an email. Basically saying, I'm moving on.  Hope things are good. I can't be friends.  etc.

He emailed back. Clearly upset by the moving on bit (which of course made me feel awful he's my babe ya know). Said that though he wasn't "moving on" that he was keeping his heart open and hoped that I would too (you never know who might come into your life) Acknowledging he figured I wouldn't be able to stay friends and thinking it was fine and probably best. But he was finding it hard to come up to Canada and not think about me, and it would be weird to come up here and not let me know. I said fine. We've had no contact since.

Skip to now. I get back from a weekend of wedding festivities on the island and there's an email from Mega Love telling me he'll be in town the 7th/8th (tomorrow) and also the 24th/25th.

And now I'm...uncertain.

Does this email need a response? I'm thinking probably. Is he just letting me know he'll be in town so that if I were to run into him at the mall I wouldn't be like "I can't believe you just showed up"? Is he telling me because he wants to hang out (but leaving it in my court since I'm the one who has been...can't hang out...can't have contact...this whole time? What is he hoping for?

And before you say well why don't you just email back and ask?

Because I don't know what my answer would be if it's anything other than him "just letting me know." 

I know I don't want to get back together.

I would love to have some wild and crazy sex.

I would not love to have sweet sex and/or make love.

I would not want to hear about him dating/dated/kissed/anything other girls.

I would love to have sex if I was able to convey to him exactly what I wanted and have him be okay with that.

I would not want to hang out/go to a movie/have dinner/have coffee/etc.

I would not want to hurt his feelings.

I would not want to get rejected.

I would not want to go back to that sad place right after we broke up, and again 2 weeks later when I realized we weren't going to be getting back together.

I would not want to lead him on.

I would like to get my freak on with someone I know isn't ridiculous.

I would like to get my freak on with someone who has ample equipment and skill/technique.

So here I am, asking for advice I guess. Can you have sex with an ex and not let it ruin the friendship? Can you hookup with an ex and not have it fuck you both up--emotionally or otherwise? When is it safe to mess around with your ex?