Pro tip: There are tools specifically made for opening jars so even if they do that, just get one of these tools and you'll never have to ask someone else to open a jar for you again. There are also ones that work with different sized Jars and even twist off bottle caps as well.
Here are some pictures of them by the way (in case anyone is in doubt of their existence):
A standard traditional one (this is what I have)
This one is marketed as "arthritis friendly"
This one is an alternative one similar to the first but with a different method of selecting size.
I'd still recommend having one just in case, even if you or your boyfriend are strong enough to open them without the tool there's always that one jar occasionally that just won't budge. For those a jar opener comes in real handy.
If these aren't affordable or accessible near you, a good substitute is nonslip shelf liner (example)
Just cut off a square big enough to comfortably drape over the lid plus the sides and it will make it much easier to open them. It requires slightly more physical ability than the jar opening tools since you need to be able to grip rather than just squeeze, but if you don't have significant hand mobility issues it should work fine.