I can find almost no information online about successfully transitioning from "lovers" to really good friends. No one expects their relationship to end, or starts one with an honest realization that this isn't forever, or goes into it seeing it as a thing to enjoy in the moment, for what it is, unless it's FWB and this is more than that.
I think you are overthinking this.
I like the John Cleese quote -- "All relationships come with a clock attached."
Even in the longest marriage -- death comes. Someone will be left widower/widow. An elder friend of mine is recently coming to terms with a beautiful marriage ending recently. So they DO end. Not even a decades long mono marriage thinks it never will end! We are not immortal humans.
Basically you are lovers and he's trying to be real and so are you. Great! Commendable! So just negotiate what you DO want your hopes in a break up to be.
I tell my DH this all the time -- "I don't want to split, but if for some crazy reason we fall out of love or something... I hope we could split amicably and still co-parent the kid well if she's still a minor."
We just talk about it. It has yet to happen -- if anything it bonds us tighter and our esteem for the other in "Thank god you are sane!" goes up.
At this time we're closed. When we were dating in though, I was involved with others and I was just honest in breaking up.
I was up front with DH at the time when he was college BF that I was not interested in exclusivity and if we were going to be together as lovers he needed to know that. He was free to date others and all I needed was health hygiene info so I could make informed decisions about my own health. That is all. I'm not a fuss pot. New lover maybe coming on board? Just tell me so I can meet/decide if our time is done or I'm ok overlapping with this person or what. And sex hygiene at ALL TIMES. I don't need disease! (I was the baby poly then he was the mono, but intrigued.)
So I had other rships. When I felt like I was moving to another time of my life with grad on the horizon...
One college ex pitched a fit because he and I dated first and I came into awareness that wait... maybe I'm not mono? So I wanted to break up because he really was
mono. So that was the decent thing to do. Break it off and be friends because he couldn't deal with poly stuff and there was a basic incompatible thing going one here.
He was annoying and causing me grief for ages and I finally got to a place where I had to suck up that he could NOT be friends with me as an ex. We broke bad. Ugh. Ugly things were said it was just ugh.
I was surprised when he called me years later to apologize for being a dunderhead and that he's since gone to counseling for his own self esteem issues. I was never sure if calling me was some kind of "therapy homework" or what. But I thanked him and since that place we've been distant pen pal type friends. He shoots me a happy bday email once in a while. I do same. We're both off married to other people. The romance is long dead but the casual friendship remains and neither wants to be tighter than we are. E-cards for holidays is good enough and I'm still amazed he was able to grow to even THAT point he was being such a big baby about things. My rejection of mono was not a rejection of HIM.
It was just basic incompatible-ness at play here. Jeez.
Now that he grew up and got over his self esteem weird I like thinking about my old Dunderhead ex. He's not so dunderhead any more.
My other college ex at the time handled the slow fade beautifully. He was bewildered why I called it thus, but circumstances with my school schedule and work schedule made it so time together was no longer lining up with him and his school/work schedule. Still liked him and cared for him fine but... life is life. Let's accept this for this semester and see what the next brings, alright? Maybe life will allow us to turn the volume back UP? We don't know. Let's be real here.
I encouraged him to see others more that maybe had better schedules and I was still around -- just not as much that semester.
He accepted all this with MUCH better grace than Dunderhead ex. Dated others, he found a GF who was threatened by me and we cut off contact the next semester. Just email or call once in a while, no hanging out. I respected she was nervy about me -- "The most recent GF now WHAT? Not quite an ex? WTF?"
So I just bowed out and made it easier on him though he was mad about it. There was no doubt in my mind that my taking a firm bow out made his life easier with HER, his main GF. So I did it. In his shoes he was all "Gah! these women make me nuts! Fine! That one bowed out. Ugh. So NOT happy about this. But maybe this one will chill out finally. God. Women!"
But when he had to do the breaking up with GF because in the end it wasn't gonna fly? He called me up to thank me for the slow fade break up thing down to "friend level" again and for bowing out firmly when he was so stressed out with her nervy.
At the time he did not understand at all and tought I was being unreasonable about the whole thing but now that the shoe was on the other foot? And HE had to let someone go, he realized how gentle I'd actually been with his heart. I was always trying to be real and be as kind as possible and consider his needs, his best interests.
So he wanted to call me to thank me for that, and that his experience with me helped him model his own later break up to a kinder thing. He also thanked me for doing the hard thing for the greater good of all and for the greater good of him -- the hard bow out when the time came. He thought at the time I was being an ugh-maker but now that he could see more clearly he appreciated what I did. I was actually being an ugh-lessener.
I cried on the phone, he cried on the phone. We mourned our old thing, because it turned out that this new thing we ended it for was also ended (and BADLY). We reminisced, we laughed, it was SO great. Best break up closure I ever had!
We never did get back together though to begin anew romantically -- mismatch kept happening. But he was my friend after until college ended and a little beyond. We were supportive of each others whatever rships that were going on as friendly sounding boards. Life took us to different corners of the world. He's not an emailer, caller, or writer though. So we lost touch and even the "friend level" thing faded to nothing over the years slowly, slowly. He's just not a good pen pal-y type person. He's him and I miss him. But I look back on him fondly and I like that a lot. He truly was great and enriched my life by being in it. The man had style and class.
So.... I don't think you are going to find some kind of perfect "how to" bullet list. People are all so different. Exes are all different type exes.
But you do know YOURSELF and how you want to be treated. List THAT.
- "If there's going to be a break up, I want to be told by...."
- "I would like to be a good ex to you. I would like to at least be.... since we have to live in the same town (or whatever it is...)"
- "Right when it is fresh though... I probably will need...."
- "In regard to physical touch as exes -- eventually maybe allow a howdy hug but when it is fresh I'm not cool/am ok with -- kissing? hugging? touching of any kind?"
But just talk it out with your lover. This is all I've ever found myself and this is way after my breakups. DH and I are closed right now raising kids. So... I don't deal in this stuff. But maybe this might help you. http://www.serolynne.com/poly_breakup.htm
Let it unfold as it will if it is to be a break up thing later, but don't not enjoy life in the NOW just because that's one possibility.
For all you know he changes his mind later and wants to stay with you and not break up at all. Or you change YOUR mind and are in some other headspace.
People keep simmering around in the Pot of Life, you know. Marinating, tenderizing, hardening, falling apart, refining, evolving who knows?
Future is future. Be real about it, but remember future isn't HERE to see either.
Don't be making NOW tempest in NOW teapots about fuzzy future. Lay out some basic "I want to be treated nicely like THIS if it is to come" and a "Let's check in ok? Like in 6 mos? See the state of the union here or if the current agreement is still working."
And let it be how it is til the check in. Then lather, rinse, repeat.
RELATIONSHIPS = there's a lot of relating back and forth going on, no? There's always something!