Gramps has a Relationship Calculator, Deep connections gramplet, “Relationship between <persons>” Person filter rule (to use in combination with the Relationship graph), Relationship to home person quickview (via gramplet or pop-up)… all for determining the relationship between distant cousins.
Most of the time, I copy the output from Pedigree gramplet for myself and the cousin to a wordprocessor and then reformat for printing. Then trim back the unrelated ancestors (and their spouses) to eliminate distractions.
But none of these are both quick and easy-to-grasp for casually sharing with that cousin.
So sometimes, I resort to View Relationship feature in FamilySearch, where there is the following chart:
I’m hoping I’ve missed something similar. Ideally, it would have the clarity of sharing Families instead of just Individuals between the cousins. (Blended families can make the line of Individuals too ambiguous.)