With your May listing and July move-out plan, your agent can suggest strategies for a smooth sale within your timeframe, including flexible closing options.

A smooth sea never produced a skilled sailor (Franklin D.

I'd try to smooth his feathers, tell him he's welcome to list you as a reference (he probably won't and they probably won't call if he does). 

Consulting with a real estate attorney or financial advisor experienced in such arrangements might provide valuable insights into making this deal happen smoothly.

Different ages , gender , interests , habits  , etc and expect things to go smoothly ?   

FSBO's almost always think their property is worth more than it is, are difficult to schedule showings with, haven't prepared the property to sell, are unwilling to negotiate, and they almost never know the sales process or have the software or the contracts to make the transaction go smoothly and keep the deal from falling apart over little things (very common when there are no agents to act as mediators, buyers and sellers have inherently opposing interests and tend to argue then cancel the deal).

Smooth sailing.

House hacking is such a smooth (for lack of better words) way to get into real estate.  

However, it is important to familiarize yourself with the legal eviction process in your area and follow all required steps to ensure a smooth eviction process.

Or should a surgeon not get paid what they get paid because the procedure only took 2 hours and it went smooth?