In a word…Yes! EVERY marital act must be both unitive and procreative. If you do not have those elements present in the act then yes it would be sinful.
I’m with Mirror, here. It sounds like what the OP is describing is mutual masturbation. To seek sexual pleasure outside of intercourse is essentially what masturbation is. “Foreplay” is something that comes prior to the marital embrace, not as a substitute.
Another strong recommendation for Mr. West.
Don’t you “get” just how wonderful it feels to pull yourself up tight to your spouse? Mr. West ought to re-examine himself and write another book. The OP stated “without orgasm”…
Within marriage, is it a mortal sin to engage in foreplay, without orgasm of either partner, and without intercourse if one partner is not fully capable of having intercourse at that time because of a pre-existing illness?
What the OP is so carefully describing is what a husband & wife do when they’re snuggling under the covers! A caress, a touch, a fondle… an expression of love & appreciation!
Depending on the circumstance it may just stop there… or progress to something else. Does physical contact between spouses HAVE TO RESULT in intercourse?
What the other replies are saying is I can’t roll over, and give my girl a squeeze or a rub under the covers of our own bed, without having it being a mortal violation of "Step 2a of the CCC rules of Conduct…a prelude to the Marital Act… subchapter 347, paragraph 987, sentence 12… that dictates the initiation of any physical contact between man & wife that results in the sexual arousal of either party must result in the expulsion of seminal fluid by the husband within his wife’s vaginal canal…?
Go back to your twin beds on opposite ends of the house.