well, give him something nice from the boys and a generic card signed by them and Maybe you. For our 25th anniversary my h (actively MLC at the time) gave me an expensive gift and acted as if all was well, although he was moving to Alaska 3 days later ( I know, I know, crazy alien).
I made him a photo album with a card saying "It's worth remembering" and I played up the family times and was more subtle on the couples things. But he seemed to think he could do what he wanted until if and when we were together, but acted like my "husband" when together UNLESS I expressed any anger or frustration, etc. Then I got the alien spew total marital revision...I mean TOTAL marital revision.
I also took the 3 kids to Italy for a trip I Wished had been an anniversary gift. But I promised myself I would be doing something great on the anniversary and not be alone. I was surprised my h came down at all, let alone for the anniversary. Like it was a grand gesture in the face of an idiot move. So I moved the trip back a few days so when he left for Alaska, WE left for Europe. (He has apologized and admitted it was a mistake but to my ears, the last week was the first time I'm sure he said it to ME...so don't hold your breath).
SO< I have to say that the trip was fantastic and proved to me and the kids we could have a blast and do a big thing, without h...and it was probably more fun without h, honestly. I'm SO GLAD I did that, no matter what my credit cards say. My kids are spread out in age, like yours. It's rare to have them on a trip all together with very little tension and a lot of memory creation. I'm glad I kept that promise to them and me, and the planning of the trip was a joy in itself. And guess what? I learned later that it bugged the crap out of my h that we'd go without him, but I had no idea he would come down to California wehre we lived (naturally he didn't have the real time for a trip to Italy and finally I did Not plan a trip around him...thank God). It was a painful signal to him that I was moving on, doing fun things, whether he was there or not. We called him once or twice but it was hard to get through. I later learned that freaked him out b/c the day we left was a terrorist day (if ykwim) and somehow he worried a lot....NOT MY PROBLEM and welcome to the worry club.
If you've gotten him something like a CD that he likes, something small, maybe go ahead. But I cannot imagine the signal you're sending by givning him a "wife"s" gift. For now, you are his "friend" or "co-parent" and your ONLY reasons for talking to him now are the kids and business --and make it important. Otherwise ,you reveal that you are not busy enough in your exciting life moving on into Your future...and you will be soon. Don't make excuses for contacting him.
Let him miss you and what it meant to be a family/husband. If you keep treating him as if he's simply on vacation of sorts, what's there to miss?
I recall I began making plans for an overseas teaching job I'd always wanted. OMG I was actually getting excited about being single and making choices for ME and the kids and not his career. I also interviewed for new jobs, some in my area and it was definitely noticed by him. Not mentioned for awhile, but noticed. Your h is noticing more than you realize.
Good luck. Wish him a happy b-day and like I said, if it's small, or from the kids, fine. Expect NOTHING substantial in return. You are only doing this small gesture because he is the father of the boys and Not to pursue or hope for a crumble of gratitude thrown your way. Besides, if it causes him guilt, it will backfire on you.
Good luck, j-
M: 57 H: 60 M: 35 yrs S30,D28,D19 H off to Alaska 2006 Recon 7/07- 8/08 *2016* X = "ALASKA 2.0" GROUND HOG DAY I File D 10/16 OW DIV 2/26/2018 X marries OW 5/2016