Lup, I have a friend who's a little younger than I am (by one week!

We were born in the same hospital). So here we are mid-50's having been through double dating, marriages, relationships, Nparents, deaths of schoolmates and those even closer... and she's currently single again. Her son is out of college now, working and in a stable relationship of his own. My friend, however, is struggling financially and is self-employed.
She's been in a relationship with a fellow craftsperson for a couple of years now. However, it's not really a "relationship"... the way we'd define a one + one relationship. He's been divorced and is extremely avoidant of even the appearance of the 2 of them being a "couple". She would like something more "conventional"... more secure... and her feelings have been hurt a couple of times, when he could've been more generous about this - but his fear of committment and having people see him as part of a couple got in the way. However, she's really enjoying what she does have with him - the romance, sex, and fun times they have together - when they do get together.
She and I are like sisters, having grown up together. She feels a little guilty about wanting more than this with her "boy-toy" and enjoying it so much and I told her: you know, you've earned the right to have a little fun with someone who doesn't want to tie you down or control every little thing you do (her last hubby was psycho-N) and it's rather sophistocated to not have a "relationship" per se - to have instead, a lover. To my way of thinking - this is romantic! It's got a bit of daring, risk, and yet, the two of them will never argue about whether the lawn got mowed or the trash was taken out or her beauty routines or girlfriends taking up too much time. Yes, it's still got it's ups and downs... but there is something attractive to me, to about this much "space" in a relationship. Of couse, I've been either married or in a close relationship most of my adult life... and I'll admit to being a little envious. I like that stage of relationships - the flirting, the courting, and even the downside of the uncertainty of if "he likes me". I keep looking for little ways to engage my hubby in this - and I think he's starting to get the idea and to "play" again! (tee-hee!)
There is some truth in the old saying, "Absence makes the heart grow fonder". After 10 years of marriage, it's very true for us. So what I'm saying here, is why not enjoy what you enjoy with M and at the same time - work on your boundaries, your degree, your home and family, your independence... and just let the relationship be "tentative"... a sometime thing... let it be what it is and enjoy that much and not worry about it being or becoming anything else?? It does simplify things a lot and let's you work on you - but not to the total exclusion of connecting with someone and having fun.
M could be your "Gennulman Friend", like Hops' guy was... but without expectations or strings attached. And it can STILL be a meaningful relationship, you know? What do you think? Is that an option for you?