<human>: Provide a brief overview of the text.

Long story short: mutually ended an 8.5 year relationship 2 months ago, but my ex now wishes we were back together.  I haven't faltered in my decision and have no desire to get back together, but things are amicable between us and we still talk a bit.  We are connected on social media, which is a mistake, but it would raise his suspicions if I delete him.

I started seeing a new guy about 3 weeks ago and we aren't officially together, but we're incredibly compatible and will probably be exclusive/official within a week or two.  I'm confident it'll last and isn't just a rebound, so no worries there.  While we aren't "in a relationship" a lot of people already know we're pretty seriously involved.

My ex went through serious surgery 2 weeks ago (all went well), but it has a long recovery and he's in a lot of physical pain right now.  I still really care about him, and don't want to make his current situation even worse by breaking the news to him before I'm publicly with the new guy, but at the same time it seems disrespectful to let him find out indirectly.  

The new guy and I are pretty anxious to start an official relationship.  My ex and I don't have many mutual friends, but we are in the same city and word gets around so it's already a bit risky, and once it's official he'll surely find out.  What would be the best timeline for telling him/starting a relationship, and how should I go about telling him?

Thanks.
<bot>: Ended 8.5 year relationship 2 months ago, getting seriously involved with a new guy and want to make things official.  How/when do I break it to my ex, considering his life situation is currently pretty shitty?